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At least 1,045 records · Page 58Linked to original sources
PubMed2002

Identification of an endo-beta-N-acetylglucosaminidase gene in Caenorhabditis elegans and its expression in Escherichia coli.

We report the identification, molecular cloning, and characterization of an endo-beta-N-acetylglucosaminidase from the nematode Caenorhabditis elegans. A search of the C. elegans genome database revealed the existence of a gene exhibiting 34% identity to Mucor hiemalis (a fungus) endo-beta-N-acetylglucosaminidase (Endo-M). Actually, the C. elegans extract contained endo-beta-N-acetylglucosaminidase activity. The putative cDNA for the C. elegans endo-beta-N-acetylglucosaminidase (Endo-CE) was amplified by polymerase chain reaction from the Uni-ZAP XR library, cloned, and sequenced. The recombinant Endo-CE expressed in Escherichia coli exhibited substrate specificity mainly for high-mannose type oligosaccharides. Man(8)GlcNAc(2) was the best substrate for Endo-CE, and Man(3)GlcNAc(2) was also hydrolyzed. Biantennary complex type oligosaccharides were poor substrates, and triantennary complex substrates were not hydrolyzed. Its substrate specificity was similar to those of Endo-M and endo-beta-N-acetylglucosaminidase from hen oviduct. Endo-CE was confirmed to exhibit transglycosylation activity, as seen for some microbial endo-beta-N-acetylglucosaminidases. This is the first report of the molecular cloning of an endo-beta-N-acetylglucosaminidase gene from a multicellular organism, which shows the possibility of using this well-characterized nematode as a model system for elucidating the role of this enzyme.

Acetylglucosaminidase↗
PubMed2002

Common exon duplication in animals and its role in alternative splicing.

When searching the genomes of human, fly and worm for cases of exon duplication, we found that about 10% of all genes contain tandemly duplicated exons. In the course of the analyses, 2438 unannotated exons were identified that are not currently included in genome databases and that are likely to be functional. The vast majority of them are likely to be involved in mutually exclusive alternative splicing events. The common nature of recent exon duplication indicates that it might have a significant role in the fast evolution of eukaryotic genes. It also provides a general mechanism for the regulation of protein function.

Alternative Splicing↗
PubMed2002

Identification of the gene responsible for the cblB complementation group of vitamin B12-dependent methylmalonic aciduria.

The methylmalonic acidurias are metabolic disorders resulting from deficient methylmalonyl-CoA mutase activity, a vitamin B(12)-dependent enzyme. We have cloned the gene for the cblB complementation group caused by deficient activity of a cob(I)alamin adenosyltransferase. This was accomplished by searching bacterial genomes for genes in close proximity to the methylmalonyl-CoA mutase gene that might encode a protein with the properties of an adenosyltransferase. A candidate was identified in the Archaeoglobus fulgidus genome and was used to probe the human genome database. It yielded a gene on chromosome 12q24 that encodes a predicted protein of 250 amino acids with 45% similarity to PduO in Salmonella enterica, a characterized cob(I)alamin adenosyltransferase. A northern blot revealed an RNA species of 1.1 kb predominating in liver and skeletal muscle. The gene was evaluated for deleterious mutations in cblB patient cell lines. Several mutations were identified including a 5 bp deletion (5del572gggcc576), two splice site mutations (IVS2-1G>T, IVS3-1G>A), andt several point mutations (A135T, R186W, R191W and E193K). Two additional amino acid substitutions (R19Q and M239K) were found in several patient cell lines but were found to be common polymorphisms (36% and 46%) in control alleles. The R186W mutation, which we suggest is disease-linked, is present in four of the six patient cell lines examined (homoallelic in two) and in 4 of 240 alleles in control samples. These data confirm that the identified gene, MMAB, corresponds to the cblB complementation group and has the appearance of a cob(I)alamin adenosyltransferase, as predicted from biochemical data.

Alkyl and Aryl Transferases↗
PubMed1999

Crooked tail (Cd) models human folate-responsive neural tube defects.

Genetic correlation of human neural tube defects (NTDs) with NTD genes identified in mouse may unravel predisposing complex traits for assessment of individual risk and treatment in clinical settings. Folic acid (FA) can reduce the recurrence of NTDs in human populations by as much as 50-70%, though the mechanism of this rescue is unknown. We examined whether Crooked tail ( Cd ), a mouse strain prone to exencephaly, could provide a genetic animal model for folate-responsive NTDs. The Cd locus was localized to a 0.2 cM interval of the Mouse Genome Database genetic map, identifying tightly linked markers for genotyping prior to phenotypic expression. In a controlled diet study, Cd was found to mimic closely the clinical response to FA. FA supplementation reduced the recurrence risk of Cd exencephaly by as much as 55%. This rescue was dose dependent and did not require subjects to be inherently folate deficient. Like the female predominance of NTDs in humans, female Cd embryos were most likely to display exencephaly and were more responsive than males to the FA rescue. Importantly, FA supplementation shifted the severity of Cd phenotypic expression from early embryonic lethality to longer survival, and reduced the incidence of NTDs. The Cd locus is distinct from the known genes associated with neurulation defects, and isolation of this gene will assist identification of biochemical, genetic and gender-dependent factors contributing to folate-responsive NTDs.

Animals↗
PubMed2000

A novel protein with RNA-binding motifs interacts with ataxin-2.

Spinocerebellar ataxia type 2 (SCA2) is caused by expansion of a polyglutamine tract in ataxin-2, a protein of unknown function. Using the yeast two-hybrid system, we identified a novel protein, A2BP1 (ataxin-2 binding protein 1) which binds to the C-terminus of ataxin-2. Northern blot analysis showed that A2BP1 was predominantly expressed in muscle and brain. By immunocfluorescent staining, A2BP1 and ataxin-2 were both localized to the trans -Golgi network. Immunocytochemistry showed that A2BP1 was expressed in the cytoplasm of Purkinje cells and dentate neurons in a pattern similar to that seen for ataxin-2 labeling. Western blot analysis of subcellular fractions indicated enrichment of A2BP1 in the same fractions as ataxin-2. Sequence analysis of the A2BP1 cDNA revealed an RNP motif that is highly conserved among RNA-binding proteins. A2BP1 had striking homology with a human cDNA clone, P83A20, of unknown function and at least two copies of A2BP1 homologs are found in the Caenorhabditis elegans genome database. A2BP1 and related proteins appear to form a novel gene family sharing RNA-binding motifs.

Adult↗
PubMed2025

Unveiling non-small cell lung cancer treatment effect heterogeneity: a comparative analysis of statistical methods.

BACKGROUND: For patients with advanced non-small cell lung cancer lacking targetable genomic alterations, the impact of clinicogenomic characteristics on the effectiveness of combining chemotherapy with immunotherapy is unclear. METHODS: We evaluated 4 statistical methods for detecting heterogeneous treatment effects related to clinical factors, including programmed death-ligand 1 expression, tumor mutation burden, and stage at diagnosis, using the American Association for Cancer Research Project Genomics Evidence Neoplasia Exchange BioPharma Collaborative dataset supplemented with institutional data collected under the same data curation model. A 2-sided P value of no more than .05 was used to denote statistical significance for all analyses. RESULTS: The mixture model revealed 2 latent subgroups: in one subgroup, there was no meaningful treatment effect, with average progression-free survival (PFS) only 5% longer with immunotherapy alone (95% confidence interval [CI] = -19% to 35%); in the second subgroup, immunotherapy alone was associated with a 35% decrease in average PFS (95% CI = -59% to 2%), corresponding to a ratio in treatment effects of 1.62 (95% CI = 1.02 to 2.57). There was a marginal association between lower tumor mutation burden levels and membership in the subgroup with improved PFS following receipt of chemoimmunotherapy. The causal survival forest highlighted the importance of tumor mutation burden (variable importance ranking: 1) and programmed death-ligand 1 (variable importance ranking: 3) when assessing heterogeneity. In contrast, the accelerated failure time and Cox proportional hazards models did not detect any statistically significant heterogeneous treatment effects. In simulations, the mixture model identified heterogeneous treatment effects more frequently than other methods, especially with weak covariate relationships, demonstrating its utility for informing personalized treatment approaches. CONCLUSIONS: The application of novel statistical methods to large scale clinico-genomic databases offers an opportunity to more accurately identify heterogeneous treatment effects in some settings as compared to traditional statistical methods. Applying such methods to the AACR Project GENIE BPC non-small cell lung cancer data indicated a potential association between decreasing tumor mutation burden and improved outcomes with chemoimmunotherapy as compared to immunotherapy alone.

Humans↗
PubMed2003

Comparison of Bayesian and maximum likelihood bootstrap measures of phylogenetic reliability.

Owing to the exponential growth of genome databases, phylogenetic trees are now widely used to test a variety of evolutionary hypotheses. Nevertheless, computation time burden limits the application of methods such as maximum likelihood nonparametric bootstrap to assess reliability of evolutionary trees. As an alternative, the much faster Bayesian inference of phylogeny, which expresses branch support as posterior probabilities, has been introduced. However, marked discrepancies exist between nonparametric bootstrap proportions and Bayesian posterior probabilities, leading to difficulties in the interpretation of sometimes strongly conflicting results. As an attempt to reconcile these two indices of node reliability, we apply the nonparametric bootstrap resampling procedure to the Bayesian approach. The correlation between posterior probabilities, bootstrap maximum likelihood percentages, and bootstrapped posterior probabilities was studied for eight highly diverse empirical data sets and were also investigated using experimental simulation. Our results show that the relation between posterior probabilities and bootstrapped maximum likelihood percentages is highly variable but that very strong correlations always exist when Bayesian node support is estimated on bootstrapped character matrices. Moreover, simulations corroborate empirical observations in suggesting that, being more conservative, the bootstrap approach might be less prone to strongly supporting a false phylogenetic hypothesis. Thus, apparent conflicts in topology recovered by the Bayesian approach were reduced after bootstrapping. Both posterior probabilities and bootstrap supports are of great interest to phylogeny as potential upper and lower bounds of node reliability, but they are surely not interchangeable and cannot be directly compared.

Animals↗
PubMed2003

Heterogeneity of nucleotide frequencies among evolutionary lineages and phylogenetic inference.

A major assumption of many molecular phylogenetic methods is the homogeneity of nucleotide frequencies among taxa, which refers to the equality of the nucleotide frequency bias among species. Changes in nucleotide frequency among different lineages in a data set are thought to lead to erroneous phylogenetic inference because unrelated clades may appear similar because of evolutionarily unrelated similarities in nucleotide frequencies. We tested the effects of the heterogeneity of nucleotide frequency bias on phylogenetic inference, along with the interaction between this heterogeneity and stratified taxon sampling, by means of computer simulations using evolutionary parameters derived from genomic databases. We found that the phylogenetic trees inferred from data sets simulated under realistic, observed levels of heterogeneity for mammalian genes were reconstructed with accuracy comparable to those simulated with homogeneous nucleotide frequencies; the results hold for Neighbor-Joining, minimum evolution, maximum parsimony, and maximum-likelihood methods. The LogDet distance method, specifically designed to deal with heterogeneous nucleotide frequencies, does not perform better than distance methods that assume substitution pattern homogeneity among sequences. In these specific simulation conditions, we did not find a significant interaction between phylogenetic accuracy and substitution pattern heterogeneity among lineages, even when the taxon sampling is increased.

Algorithms↗
PubMed2005

Diversity and evolution of the thyroglobulin type-1 domain superfamily.

Multidomain proteins are gaining increasing consideration for their puzzling, flexible utilization in nature. The presence of the characteristic thyroglobulin type-1 (Tg1) domain as a protein module in a variety of multicellular organisms suggests pivotal roles for this building block. To gain insight into the evolution of Tg1 domains, we performed searches of protein, expressed sequence tag, and genome databases. Tg1 domains were found to be Metazoa specific, and we retrieved a total of 170 Tg1 domain-containing protein sequences. Their architectures revealed a wide taxonomic distribution of proteins containing Tg1 domains followed or preceded by secreted protein, acidic, rich in cysteines (SPARC)-type extracellular calcium-binding domains. Other proteins contained lineage-specific domain combinations of peptidase inhibitory modules or domains with different biological functions. Phylogenetic analysis showed that Tg1 domains are highly conserved within protein structures, whereas insertion into novel proteins is followed by rapid diversification. Seven different basic types of protein architecture containing the Tg1 domain were identified in vertebrates. We examined the evolution of these protein groups by combining Tg1 domain phylogeny with additional analyses based on other characteristic domains. Testicans and secreted modular calcium binding protein (SMOCs) evolved from invertebrate homologs by introduction of vertebrate-specific domains, nidogen evolved by insertion of a Tg1 domain into a preexisting architecture, and the remaining four have unique architectures. Thyroglobulin, Trops, and the major histocompatibility complex class II-associated invariant chain are vertebrate specific, while an insulin-like growth factor-binding protein and nidogen were also identified in urochordates. Among vertebrates, we observed differences in protein repertoires, which result from gene duplication and domain duplication. Members of five groups have been characterized at the molecular level. All exhibit subtle differences in their specificities and function either as peptidase inhibitors (thyropins), substrates, or both. As far as the sequence is concerned, only a few conserved residues were identified. In combination with structural data, our analysis shows that the Tg1 domain fold is highly adaptive and comprises a relatively well-conserved core surrounded by highly variable loops that account for its multipurpose function in the animal kingdom.

Amino Acid Sequence↗
PubMed2002

A 60-66 kDa protein with gonadotrophin surge attenuating factor bioactivity is produced by human ovarian granulosa cells.

We aimed to confirm the ovarian site of gonadotrophin surge-attenuating factor (GnSAF) production and produce granulosa/luteal cell-conditioned medium (G/LCM) containing GnSAF for purification studies. Blue dye affinity chromatography followed by pseudochromatofocusing of G/LCM yielded bioactive fractions at pH 5.74 and 5.77. The former had a major 60-66 kDa band with an internal amino acid sequence of EPQVYVHAP following tryptic digestion. A rat polyclonal antiserum (rPAb) raised against this band completely blocked in-vitro GnSAF bioactivity in human follicular fluid, serum and G/LCM. GnSAF bioactivity was localized to a 64 kDa band of serum-free G/LCM and following 2D gel electrophoresis, one of the spots recognized by Western blotting with the GnSAF rPAb had an N-terminal amino acid sequence of NH-XVPQGNAXXN. Neither amino acid sequence had significant homology with proteins in the human genome database. When ovarian tissues from spontaneously cycling women were cultured under serum-free conditions, neither theca- nor stroma-conditioned media contained GnSAF bioactivity. However, granulosa cell-conditioned medium significantly reduced GnRH-induced LH secretion, an effect that was reversed by incubation with the GnSAF rPAb. In conclusion, we have confirmed that human granulosa cells produce GnSAF within the ovary and have two candidate amino acid sequences for GnSAF. We have also demonstrated that serum-free granulosa cell culture constitutes the method of choice for the characterization of GnSAF since recovery of bioactivity is superior in the presence of fewer serum proteins.

Biological Factors↗
PubMed2004

Increased expression of the FIGLA transcription factor is associated with primordial follicle formation in the human fetal ovary.

The process of primordial follicle formation is central to the determination of a woman's reproductive lifespan, and in humans occurs towards the end of mid-gestation. Gene knockout analysis in the mouse has shown that Figla, a transcription factor specifically expressed in germ cells, is essential for oocytes to survive and form primordial follicles. Our objective was to investigate whether a human homologue present in the genome database plays a similar role in human ovary development. Standard and real-time RT-PCR demonstrated that the human FIGLA gene is expressed in the fetal ovary but not by a range of other tissues, and that expression increases across mid-gestation, rising some 40-fold by the time of primordial follicle formation. The entire coding sequence was cloned and new exonic sequences identified. Electrophoretic mobility shift assays with in vitro-expressed human FIGLA protein showed that, as in the mouse, FIGLA can heterodimerize with E12 protein and bind to the E-box of the human ZP2 promoter. Similar mobility shifts were identified in human fetal ovary extracts. These results suggest that FIGLA is involved in continued oocyte survival as primordial follicles form in the human as in the rodent ovary.

Amino Acid Sequence↗
PubMed2000

The microarray explorer tool for data mining of cDNA microarrays: application for the mammary gland.

The Microarray Explorer (MAExplorer) is a versatile Java-based data mining bioinformatic tool for analyzing quantitative cDNA expression profiles across multiple microarray platforms and DNA labeling systems. It may be run as either a stand-alone application or as a Web browser applet over the Internet. With this program it is possible to (i) analyze the expression of individual genes, (ii) analyze the expression of gene families and clusters, (iii) compare expression patterns and (iv) directly access other genomic databases for clones of interest. Data may be downloaded as required from a Web server or in the case of the stand-alone version, reside on the user's computer. Analyses are performed in real-time and may be viewed and directly manipulated in images, reports, scatter plots, histograms, expression profile plots and cluster analyses plots. A key feature is the clone data filter for constraining a working set of clones to those passing a variety of user-specified logical and statistical tests. Reports may be generated with hypertext Web access to UniGene, GenBank and other Internet databases for sets of clones found to be of interest. Users may save their explorations on the Web server or local computer and later recall or share them with other scientists in this groupware Web environment. The emphasis on direct manipulation of clones and sets of clones in graphics and tables provides a high level of interaction with the data, making it easier for investigators to test ideas when looking for patterns. We have used the MAExplorer to profile gene expression patterns of 1500 duplicated genes isolated from mouse mammary tissue. We have identified genes that are preferentially expressed during pregnancy and during lactation. One gene we identified, carbonic anhydrase III, is highly expressed in mammary tissue from virgin and pregnant mice and in gene knock-out mice with underdeveloped mammary epithelium. Other genes, which include those encoding milk proteins, are preferentially expressed during lactation.

Animals↗
PubMed2001

Interspecies conservation of gene order and intron-exon structure in a genomic locus of high gene density and complexity in Plasmodium.

A 13.6 kb contig of chromosome 5 of Plasmodium berghei, a rodent malaria parasite, has been sequenced and analysed for its coding potential. Assembly and comparison of this genomic locus with the orthologous locus on chromosome 10 of the human malaria Plasmodium falciparum revealed an unexpectedly high level of conservation of the gene organisation and complexity, only partially predicted by current gene-finder algorithms. Adjacent putative genes, transcribed from complementary strands, overlap in their untranslated regions, introns and exons, resulting in a tight clustering of both regulatory and coding sequences, which is unprecedented for genome organisation of PLASMODIUM: In total, six putative genes were identified, three of which are transcribed in gametocytes, the precursor cells of gametes. At least in the case of two multiple exon genes, alternative splicing and alternative transcription initiation sites contribute to a flexible use of the dense information content of this locus. The data of the small sample presented here indicate the value of a comparative approach for Plasmodium to elucidate structure, organisation and gene content of complex genomic loci and emphasise the need to integrate biological data of all Plasmodium species into the P.falciparum genome database and associated projects such as PlasmodB to further improve their annotation.

Alternative Splicing↗
PubMed2004

iMOT: an interactive package for the selection of spatially interacting motifs.

Functional selection and three-dimensional structural constraints of proteins relate to the retention of significant sequence similarity between proteins of similar fold and function despite poor overall sequence identity and evolutionary pressures. We report the availability of 'iMOT' (interacting MOTif) server, an interactive package for the automatic identification of spatially interacting motifs among distantly related proteins sharing similar folds and possessing common ancestral lineage. Spatial interactions between conserved stretches of a protein are evaluated by calculations of pseudo-potentials that describe the strength of interactions. Such an evaluation permits the automatic identification of highly interacting conserved regions of a protein. Interacting motifs have been shown to be useful in searching for distant homologues and establishing remote homologies among the largely unassigned sequences in genome databases. Information on such motifs should also be of value in protein folding, modelling and engineering experiments. The iMOT server can be accessed from http://www.ncbs.res.in/~faculty/mini/imot/iMOTserver.html. Supplementary Material can be accessed from: http://www.ncbs.res.in/~faculty/mini/imot/supplementary.html.

Amino Acid Motifs↗
PubMed2006

The WD40-repeat protein Pwp1p associates in vivo with 25S ribosomal chromatin in a histone H4 tail-dependent manner.

The tails of core histones (H2A, H2B, H3 and H4) are critical for the regulation of chromatin dynamics. Each core histone tail is specifically recognized by various tail binding proteins. Here we screened for budding yeast histone H4-tail binding proteins in a protein differential display approach by two-dimensional gel electrophoresis (2DGE). To obtain highly enriched chromatin proteins, we used a Mg2+-dependent chromatin oligomerization technique. The Mg2+-dependent oligomerized chromatin from H4-tail deleted cells was compared with that from wild-type cells. We used mass spectrometry to identify 22 candidate proteins whose amounts were reduced in the oligomerized chromatin from the H4-tail deleted cells. A Saccharomyces Genome Database search revealed 10 protein complexes, each of which contained more than two candidate proteins. Interestingly, 7 out of the 10 complexes have the potential to associate with the H4-tail. We obtained in vivo evidence, by a chromatin immunoprecipitation assay, that one of the candidate proteins, Pwp1p, associates with the 25S ribosomal DNA (rDNA) chromatin in an H4-tail-dependent manner. We propose that the complex containing Pwp1p regulates the transcription of rDNA. Our results demonstrate that the protein differential display approach by 2DGE, using a histone-tail mutant, is a powerful method to identify histone-tail binding proteins.

Chromatin↗
PubMed1999

A fission yeast gene (prr1(+)) that encodes a response regulator implicated in oxidative stress response.

An inspection of the Schizosaccharomyces pombe genome database revealed that this eukaryotic microorganism possesses a gene that may encode a bacterial type of histidine-to-aspartate (His-Asp) phosphorelay component, namely, a response regulator. The predicted gene, named prr1(+) (S. pombe response regulator), encodes a protein that contains a typical phospho-accepting receiver domain, preceded by a mammalian heat shock factor (HSF)-like DNA-binding domain. Inactivation of this prr1(+) gene resulted in mutant cells defective in some aspects of stress responses, including sensitivity to oxidative stress, cold-temperature, and heavy metal toxicity. It was also demonstrated that Prr1 is required for the transcription of some genes (e.g., trr1(+), ctt1(+)), which are induced by oxidative stress. These results suggest that a His-Asp phosphorelay system may be involved in a stress-activated signaling pathway in S. pombe.

Aspartic Acid↗
PubMed2003

Distinct expression and function of three ammonium transporter genes (OsAMT1;1-1;3) in rice.

To study the regulation of ammonium uptake into rice roots, three ammonium transporter genes (OsAMT1;1, 1;2 and 1;3; Oryza sativa ammonium transporter) were isolated and examined. OsAMT1s belong to AMT1 family, containing 11 putative transmembrane-spanning domains. Southern blot analysis and screening of the rice genome database confirmed that with OsAMT1;1-1;3 the complete AMT1 family of rice had been isolated. Heterologous expression of OsAMT1s in the yeast Saccharomyces cerevisiae mutant 31019b showed that all three OsAMT1s exhibit ammonium transport activity. Northern blot analysis showed a distinct expression pattern for the three genes; more constitutive expression in shoots and roots for OsAMT1;1, root-specific and ammonium-inducible expression for OsAMT1;2, and root-specific and nitrogen-derepressible expression for OsAMT1;3. In situ mRNA detection revealed that OsAMT1;2 is expressed in the central cylinder and cell surface of root tips. This gene expression analysis revealed a distinct nitrogen-dependent regulation for AMTs in rice, differing from that in tomato or Arabidopsis:

Amino Acid Sequence↗
PubMed2005

Catalysis, subcellular localization, expression and evolution of the targeting peptides degrading protease, AtPreP2.

We have previously identified a zinc metalloprotease involved in the degradation of mitochondrial and chloroplast targeting peptides, the presequence protease (PreP). In the Arabidopsis thaliana genomic database, there are two genes that correspond to the protease, the zinc metalloprotease (AAL90904) and the putative zinc metalloprotease (AAG13049). We have named the corresponding proteins AtPreP1 and AtPreP2, respectively. AtPreP1 and AtPreP2 show significant differences in their targeting peptides and the proteins are predicted to be localized in different compartments. AtPreP1 was shown to degrade both mitochondrial and chloroplast targeting peptides and to be dual targeted to both organelles using an ambiguous targeting peptide. Here, we have overexpressed, purified and characterized proteolytic and targeting properties of AtPreP2. AtPreP2 exhibits different proteolytic subsite specificity from AtPreP1 when used for degradation of organellar targeting peptides and their mutants. Interestingly, AtPreP2 precursor protein was also found to be dual targeted to both mitochondria and chloroplasts in a single and dual in vitro import system. Furthermore, targeting peptide of the AtPreP2 dually targeted green fluorescent protein (GFP) to both mitochondria and chloroplasts in tobacco protoplasts and leaves using an in vivo transient expression system. The targeting of both AtPreP1 and AtPreP2 proteases to chloroplasts in A. thaliana in vivo was confirmed via a shotgun mass spectrometric analysis of highly purified chloroplasts. Reverse transcription-polymerase chain reaction (RT-PCR) analysis revealed that AtPreP1 and AtPreP2 are differentially expressed in mature A. thaliana plants. Phylogenetic evidence indicated that AtPreP1 and AtPreP2 are recent gene duplicates that may have diverged through subfunctionalization.

Amino Acid Sequence↗