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PubMed1983

Nucleotide sequence of Rous sarcoma virus.

We present the 9312 nucleotide sequence of the Prague C (Pr-C) strain of Rous sarcoma virus (RSV). A comparison of known protein sequences with the nucleotide sequence allows assignment of the coding regions for the gag, pol, env and src genes. The gag gene is terminated by an amber stop codon and is contained within a different reading frame than is the pol gene. The pol and env genes overlap. The sequences surrounding the src gene in the Pr-C and Schmidt-Ruppin (SR-A) strains of RSV have been compared, and they reveal that an element, E, of approximately 153 nucleotides is present on the 3' side of the src gene in Pr-C, and on the 5' side in SR-A. We hypothesize that E was part of a duplicated region of over 250 nucleotides flanking the src gene in an ancestral RSV, and that differential deletion of one copy of E led to its positional difference in Pr-C and SR-A.

Amino Acid Sequence↗
PubMed2005

Genetic characterization of the mitochondrial DNA from Lepeophtheirus salmonis (Crustacea; Copepoda). A new gene organization revealed.

The mitochondrial DNA (mtDNA) from the salmon louse, Lepeophtheirus salmonis, is 15445 bp. It includes the genes coding for cytochrome B (Cyt B), ATPase subunit 6 and 8 (A6 and A8), NADH dehydrogenase subunits 1-6 and 4L (ND1, ND2, ND3, ND4, ND4L, ND5 and ND6), cytochrome c oxidase subunits I-III (COI, COII and COIII), two rRNA genes (12S rRNA and 16S rRNA) and 22 tRNAs. Two copies of tRNA-Lys are present in the mtDNA of L. salmonis, while tRNA-Cys was not identified. Both DNA strands contain coding regions in the salmon louse, in contrast to the other copepod characterized Tigriopus japonicus, but only a few genes overlap. In vertebrates, ND4 and ND4L are transcribed as one bicistronic mRNA, and are therefore localized together. The same organization is also found in crustaceans, with the exceptions of T. japonicus, Neocalanus cristatus and L. salmonis that deviate from this pattern. Another exception of the L. salmonis mtDNA is that A6 and A8 do not overlap, but are separated by several genes. The protein-coding genes have a bias towards AT-rich codons. The mitochondrial gene order in L. salmonis differs significantly from the copepods T. japonicus, Eucalanus bungii, N. cristatus and the other 13 crustaceans previously characterized. Furthermore, the mitochondrial rRNA genes are encoded on opposite strands in L. salmonis. This has not been found in any other arthropods, but has been reported in two starfish species. In a phylogenetic analysis, using an alignment of mitochondrial protein sequences, L. salmonis groups together with T. japonicus, being distant relatives to the other crustaceans.

Animals↗
PubMed2001

Structure, chromosomal localization, and expression of the gene for mouse ecto-mono(ADP-ribosyl)transferase ART5.

Mono(ADP-ribosyl)transferases regulate the function of target proteins by attaching ADP-ribose to specific amino acid residues in their target proteins. The purpose of this study was to determine the structure, chromosomal localization, and expression profile of the gene for mouse ecto-ADP-ribosyltransferase ART5. Southern blot analyses indicate that Art5 is a single copy gene which maps to mouse chromosome 7 at offset 49.6 cM in close proximity to the Art1, Art2a and Art2b genes. Northern blot and RT-PCR analyses demonstrate prominent expression of Art5 in testis, and lower levels in cardiac and skeletal muscle. Sequence analyses reveal that the Art5 gene encompasses six exons spanning 8 kb of genomic DNA. The 5' end of the Art5 gene overlaps with that of the Art1 gene. A single long exon encodes the predicted ART5 catalytic domain. Separate exons encode the N-terminal leader peptide and a hydrophilic C-terminal extension. Sequencing of RT-PCR products and ESTs identified six splice variants. The deduced amino acid sequence of ART5 shows 87% sequence identity to its orthologue from the human, and 37 and 32% identity to its murine paralogues ART1 and ART2. Unlike ART1 and ART2, ART5 lacks a glycosylphosphatidylinositol-anchor signal sequence and is predicted to be a secretory enzyme. This prediction was confirmed by transfecting an Art5 cDNA expression construct into Sf9 insect cells. The secreted epitope-tagged ART5 protein resembled rat ART2 in exhibiting potent NAD-glycohydrolase activity. This study provides important experimental tools to further elucidate the function of ART5.

ADP Ribose Transferases↗
PubMed2006

Interleukin-5 regulates genes involved in B-cell terminal maturation.

Interleukin (IL)-5 induces CD38-activated splenic B cells to differentiate into immunoglobulin M-secreting cells and undergo micro to gamma 1 class switch recombination (CSR) at the DNA level, resulting in immunoglobulin G1 (IgG1) production. Interestingly, IL-4, a well-known IgG1-inducing factor does not induce immunoglobulin production or micro to gamma 1 CSR in CD38-activated B cells. In the present study, we implemented complementary DNA microarrays to investigate the contribution of IL-5-induced gene expression in CD38-stimulated B cells to immunoglobulin-secreting cell differentiation and micro to gamma 1 CSR. IL-5 and IL-4 stimulation of CD38-activated B cells induced the expression of 418 and 289 genes, respectively, that consisted of several clusters. Surprisingly, IL-5-inducible 78 genes were redundantly regulated by IL-4. IL-5 and IL-4 also suppressed the gene expression of 319 and 325 genes, respectively, 97 of which were overlapped. Genes critically regulated by IL-5 include immunoglobulin-related genes such as J chain and immunoglobulinkappa, and genes involved in B-cell maturation such as BCL6, activation-induced cytidine deaminase (Aid) and B lymphocyte-induced maturation protein-1 (Blimp-1) and tend to be induced slowly after IL-5 stimulation. Intriguingly, among genes, the retroviral induction of Blimp-1 and Aid in CD38-activated B cells could induce IL-4-dependent maturation to Syndecan-1+ antibody-secreting cells and micro to gamma 1 CSR, respectively, in CD38-activated B cells. Taken together, preferential Aid and Blimp-1 expression plays a critical role in IL-5-induced immunoglobulin-secreting cell differentiation and micro to gamma 1 CSR in CD38-activated B cells.

ADP-ribosyl Cyclase 1↗
PubMed1982

Nucleotide sequence analyses and predicted coding of bunyavirus genome RNA species.

We performed 3' RNA sequence analyses of [(32)P]pCp-end-labeled La Crosse (LAC) virus, alternate LAC virus isolate L74, and snowshoe hare bunyavirus large (L), medium (M), and small (S) negative-stranded viral RNA species to determine the coding capabilities of these species. These analyses were confirmed by dideoxy primer extension studies in which we used a synthetic oligodeoxynucleotide primer complementary to the conserved 3'-terminal decanucleotide of the three viral RNA species (Clerx-van Haaster and Bishop, Virology 105:564-574, 1980). The deduced sequences predicted translation of two S-RNA gene products that were read in overlapping reading frames. So far, only single contiguous open reading frames have been identified for the viral M- and L-RNA species. For the negative-stranded M-RNA species of all three viruses, the single reading frame developed from the first 3'-proximal UAC triplet. Likewise, for the L-RNA of the alternate LAC isolate, a single open reading frame developed from the first 3'-proximal UAC triplet. The corresponding L-RNA sequences of prototype LAC and snowshoe hare viruses initiated open reading frames; however, for both viral L-RNA species there was a preceding 3'-proximal UAC triplet in another reading frame that was followed shortly afterward by a termination codon. A comparison of the sequence data obtained for snowshoe hare virus, LAC virus, and the alternate LAC virus isolate showed that the identified nucleotide substitutions were sufficient to account for some of the fingerprint differences in the L-, M-, and S-RNA species of the three viruses. Unlike the distribution of the L- and M-RNA substitutions, significantly fewer nucleotide substitutions occurred after the initial UAC triplet of the S-RNA species than before this triplet, implying that the overlapping genes of the S RNA provided a constraint against evolution by point mutation. The comparative sequence analyses predicted amino acid differences among the corresponding L-, M-, and S-RNA gene products of snowshoe hare virus and the two LAC virus isolates.

Base Sequence↗
PubMed2026

Investigating the mechanisms of PhIP-induced colorectal cancer through network toxicology, machine learning, and molecular dynamics simulation.

BACKGROUND: Over the past few years, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)- a compound from grilled or processed meats-has emerged as a major player in cancer development, especially colorectal cancer (CRC). This work dives into its potential links to CRC and uncovers the key genes that bridge this connection. METHODS: We tapped into various databases to pinpoint target genes tied to PhIP and CRC, then ran protein-protein interaction (PPI) analyses for visualization. Next, we explored underlying mechanisms through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. To nail down predictions, we tested 107 machine learning pipelines and picked the best one, validating its accuracy and the core genes' prognostic value across datasets. Next, molecular docking and dynamics simulations probed the interactions between these genes and PhIP. Finally, cell proliferation was assessed using Cell Counting Kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) assays, and polymerase chain reaction (PCR) was performed to validate the expression levels of the hub genes. RESULTS: Our analysis identified 39 overlapping genes, from which a machine learning model (glmBoost + Enet) identified six candidate targets: CDK4, CEBPB, COMT, SOX9, TIMP1, and TOP2A. To prioritize these, a hierarchical screening framework was applied. Molecular docking and dynamics simulations identified CDK4, COMT, and TIMP1 as the most stable interactors with PhIP. Functional assays confirmed that PhIP treatment significantly enhanced the proliferation of CRC cells. Crucially, quantitative PCR (qPCR) validation in multiple CRC cell lines identified TIMP1 as the primary target, showing the most consistent and significant upregulation upon PhIP exposure. CONCLUSIONS: In essence, these genes drive PhIP is role in CRC, offering novel insights into its molecular pathways. This could reshape how we tackle food-related pollutants, paving the way for better prevention and targeted therapies.

Colorectal cancer (CRC)↗
PubMed1995

Mutation of the htrB locus of Haemophilus influenzae nontypable strain 2019 is associated with modifications of lipid A and phosphorylation of the lipo-oligosaccharide.

The HtrB protein was first identified in Escherichia coli as a protein required for cell viability at high temperature, but its expression was not regulated by temperature. We isolated an htrB homologue from non-typable Haemophilus influenzae strain (NTHi) 2019, which was able to functionally complement the E. coli htrB mutation. The promoter for the NTHi 2019 htrB gene overlaps the promoter for the rfaE gene, and the two genes are divergently transcribed. The deduced amino acid sequence of NTHi 2019 HtrB had 56% homology to E. coli HtrB. In vitro transcription-translation analysis confirmed production of a protein with an apparent molecular mass of 32-33 kDa. Primer extension analysis revealed that htrB was transcribed from a sigma 70-dependent consensus promoter and its expression was not affected by temperature. The expression of htrB and rfaE was 2.5-4 times higher in the NTHi htrB mutant B29 than in the parental strain. In order to study the function of the HtrB protein in Haemophilus, we generated two isogenic htrB mutants by shuttle mutagenesis using a mini-Tn3. The htrB mutants initially showed temperature sensitivity, but they lost the sensitivity after a few passages at 30 degrees C and were able to grow at 37 degrees C. They also showed hypersensitivity to deoxycholate and kanamycin, which persisted on passage. SDS-polyacrylamide gel electrophoresis analysis revealed that the lipo-oligosaccharide (LOS) isolated from these mutants migrated faster than the wild type LOS and its color changed from black to brown as has been described for E. coli htrB mutants. Immunoblotting analysis also showed that the LOS from the htrB mutants lost reactivity to a monoclonal antibody, 6E4, which binds to the wild type NTHi 2019 LOS. Electrospray ionization-mass spectrometry analysis of the O-deacylated LOS oligosaccharide indicated a modification of the core structure characterized in part by a net loss in phosphoethanolamine. Mass spectrometric analysis of the lipid A of the htrB mutant indicated a loss of one or both myristic acid substitutions. These data suggest that HtrB is a multifunctional protein and may play a controlling role in regulating cell responses to various environmental changes.

Bacterial Proteins↗
PubMed1985

The amino terminal half of the MS2-coded lysis protein is dispensable for function: implications for our understanding of coding region overlaps.

We have asked whether genetic overlaps only evolve to provide extra coding capacity in genomes of restricted size. As a model system we have used the lysis gene of the RNA bacteriophage MS2. This gene overlaps with the distal part of the coat protein gene and with the proximal part of the replicase gene. Using recombinant DNA procedures we have determined whether either of the two overlaps codes for amino acids that are not essential for the function of the 75 amino acid long lysis protein. We find that the first 40 amino acids of the lysis protein are dispensable for function. Thus all of the genetic information essential to the synthesis of the active C-terminal peptide lies within the overlap with the replicase gene, whereas all dispensable residues are encoded in the overlap with the coat protein gene and in the intercistronic region. This suggests that the overlap with the coat protein gene is not required for extra coding capacity but serves to regulate the expression of the lysis gene. Comparative sequence analysis is consistent with this idea.

Amino Acid Sequence↗
PubMed1990

TGATG vector: a new expression system for cloned foreign genes in Escherichia coli cells.

A TGATG vector system was developed that allows for the construction of hybrid operons with partially overlapping genes, employing the effects of translational coupling to optimize expression of cloned cistrons in Escherichia coli. In this vector system (plasmid pPR-TGATG-1), the coding region of a foreign gene is attached to the ATG codon situated on the vector, to form the hybrid operon transcribed from the phage lambda PR promoter. The cloned gene is the distal cistron of this hybrid operon ('overlappon'). The efficiently translated cro'-cat'-'trpE hybrid cistron is proximal to the promoter. The coding region of this artificial fused cistron [the length of the corresponding open reading frame is about 120 amino acids (aa)] includes the following: the N-terminal portions of phage lambda Cro protein (20 aa), the CAT protein of E. coli (72 aa) and 3' C-terminal codons of the E. coli trpE gene product. At the 3'-end of the cro'-cat'-'trpE fused cistron there is a region for efficient translation reinitiation: a Shine-Dalgarno sequence of the E. coli trpD gene and the overlapping stop and start codons (TGATG). In this sequence, the last G is the first nucleotide of the unique SacI-recognition site (GAGCT decreases C) and so integration of the structural part of the foreign gene into the vector plasmid may be performed using blunt-end DNA linking after the treatment of pPR-TGATG-1 with SacI and E. coli DNA polymerase I or its Klenow fragment.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1999

The S7 ribosomal protein gene is truncated and overlaps a cytochrome c biogenesis gene in pea mitochondria.

The pea mitochondrial genome contains a truncated rps7 gene lacking ca. 40 codons at its 5' terminus. This single-copy sequence is immediately downstream of and slightly overlapping an actively transcribed and edited reading frame of 744 bp (designated ccb248) homologous to the bacterial helC gene which encodes a subunit of the ABC-type heme transporter involved in cytochrome c biogenesis. This region of mitochondrial DNA appears recombinogenic, and the carboxy-termini of helC-type proteins are predicted to vary in sequence and length among plants. Sequences corresponding to the 5' coding region of rps7 were not detected elsewhere in the pea mitochondrial genome using wheat rps7 probes, and only a very short internal rps7 segment was observed in soybean mitochondrial DNA. The presence of rps7-homologous sequences in the nuclear genomes of pea and soybean is consistent with the recent transfer of a functional mitochondrial rps7 gene to the nucleus in certain plant lineages.

ATP-Binding Cassette Transporters↗
PubMed2005

Overlap of the gene encoding the novel poly(ADP-ribose) polymerase Parp10 with the plectin 1 gene and common use of exon sequences.

We have recently identified PARP10 as a novel functional poly(ADP-ribose) polymerase. The gene encoding PARP10 is conserved in vertebrates but no orthologs were found in lower organisms. In addition to the poly(ADP-ribose) polymerase domain, PARP10 possesses several additional sequence motifs, including an RNA recognition motif and two ubiquitin interaction motifs. We characterized the murine genomic locus of the Parp10 gene. We noticed that 3' Parp10 sequences overlapped with the plectin 1 gene in a head-to-tail arrangement. Detailed analyses revealed that the two most 3' Parp10 exons (exons 10 and 11) are also used for plectin 1. While these two exons code for part of the poly(ADP-ribose) polymerase domain in Parp10, they are noncoding for plectin 1 due to the lack of appropriate start codons. Furthermore our findings suggest that at least one of the plectin 1 promoters is located within intron 9 of the Parp10 gene.

Amino Acid Sequence↗
PubMed2006

Hepatitis B virus mutations associated with antiviral therapy.

The hepatitis B virus (HBV) replicates via an error prone viral reverse transcriptase resulting in a large pool of quasispecies with mutations spread throughout the genome. During antiviral drug selection pressure (e.g., lamivudine, adefovir, or entecavir) HBV mutants are selected from the pre-existing pool of quasispecies and over time become the dominant species. Not all mutations result in replication competent virus as HBV has the added complexity of overlapping reading frames. The HBV polymerase (Pol) gene overlaps the hepatitis B surface antigen (HBsAg) in a frame-shifted manner with the result that drug-resistant mutations in the HBV Pol can directly impact on the nature of HBsAg and its function. HBV genomic databases have been established to monitor antiviral selected mutations and are useful in determining conserved residues, genotypic differences, polymorphisms, and the mutation profiles selected under different antiviral selection pressures. These HBV databases may aid in the development of new diagnostic reagents as well as the monitoring of polymerase and envelope mutations selected under different antiviral pressures. Antiviral drug resistant mutants emerge as a function of at least six factors: the viral mutation frequency, the intrinsic mutability of the antiviral target site, the selective pressure exerted by the drug, the magnitude and rate of virus replication, the overall replication fitness of the mutant, and the availability of replication space. Only a limited number of HBsAg mutations selected during antiviral treatment have been characterized and the diagnostic and public health implications of these mutations need further investigation. Clearly, improved treatment strategies are required urgently to prevent the continued selection of HBV drug-resistant mutants.

Antiviral Agents↗
PubMed1979

Normal tRNAs promote ribosomal frameshifting.

The addition of Ser AGC AGU tRNA to an E. coli cell-free protein synthesizing system which contains the endogenous tRNA levels results in up to 100% of the ribosomes translating the MS2 coat gene shifting into the -1 reading frame. An analogous phenomenon is seen at a much lower level without the tRNA addition, where a shift into the +1 frame can also be detected. Thus translation with the endogenous tRNA levels yields proteins which have the amino terminus of the coat protein but which are substantially larger than the coat protein and comprise about 5% of the coat translation. Since the lysis gene overlaps the 3' end of the coat gene in the +1 frame, we conclude that the reading frame shift into the +1 frame yields a hybrid protein. Also, we present evidence that ribosomes translating the synthetase gene shift into the -1 frame near the distal end of the gene. This frameshifting is promoted by thrACU ACC tRNA. Specific competitor tRNAs for both Thr and Ser tRNA-promoted frameshifting have been characterized. The generality of this new mechanism for producing additional proteins is unclear, but it investigation should increase understanding of the coding mechanism and its origin.

Amino Acid Sequence↗
PubMed2006

The mitochondrial genome of Priapulus caudatus Lamarck (Priapulida: Priapulidae).

We sequenced and annotated the complete mitochondrial (mt) genome of the priapulid Priapulus caudatus in order to provide a source of phylogenetic characters including an assessment of gene order arrangement. The genome was 14,919 bp in its entirety with few, short non-coding regions. A number of protein-coding and tRNA genes overlapped, making the genome relatively compact. The gene order was: cox1, cox2, trnK, trnD, atp8, atp6, cox3, trnG, nad3, trnA, trnR, trnN, rrnS, trnV, rrnL, trnL(yaa), trnL(nag), nad1, -trnS(nga), -cob, -nad6, trnP, -trnT, nad4L, nad4, trnH, nad5, trnF, -trnE, -trnS(nct), trnI, -trnQ, trnM, nad2, trnW, -trnC, -trnY; where '-' indicates genes transcribed on the opposite strand. The gene order, although unique amongst Metazoa, shared the greatest number of gene boundaries and the longest contiguous fragments with the chelicerate Limulus polyphemus. The mt genomes of these taxa differed only by a single inversion of 18 contiguous genes bounded by rrnS and trnS(nct). Other arthropods and nematodes shared fewer gene boundaries but considerably more than the most similar non-ecdysozoan.

Animals↗
PubMed1997

Identification and DNA sequence analysis of the Marek's disease virus serotype 2 genes homologous to the thymidine kinase and UL24 genes of herpes simplex virus type 1.

The thymidine kinase (TK) gene has been used as a safe and convenient locus for expression of heterologous proteins in some alphaherpesviruses including herpesvirus of turkeys (HVT) antigenically related to Marek's disease virus (MDV) serotypes 1 (MDV1) and 2 (MDV2). In MDV2 strain HPRS 24 genome, genes equivalent to the TK and UL24 homologues of herpes simplex virus type 1 were identified and sequenced. The MDV2 UL24 gene overlaps the 5' end of the TK gene in a head-to-head orientation. The predicted region encoding for the MDV2 TK gene is 1,056 nucleotides, corresponding to a polypeptide of 352 amino acids in length. Putative nucleotide- and thymidine-binding sites were identified within the predicted amino acid sequence. The predicted region encoding for the UL24 gene is 948 nucleotides, corresponding to a polypeptide of 316 amino acids in length. By northern blot analyses using MDV2 TK- and UL24-specific DNA probes, four transcripts of approximately 7.8, 5.0, 3.5, and 1.1 kb for the TK gene, and a transcript of 3.8 kb for the UL24 gene were detected in MDV2-infected cells. Alignment of the amino acid sequence of MDV2 TK homologue with those published for TK homologues of other MDV serotypes showed 73.9% (MDV1 vs. MDV2), 58.2% (MDV1 vs. HVT), and 56.8% (MDV2 vs. HVT) identities. Comparison to other alphaherpesvirus TK homologues revealed amino acid sequence homologies varying from 34.5% to 27.8%. The putative MDV2 UL24 homologous protein had identity with the well conserved five motifs among alphaherpesviruses.

Amino Acid Sequence↗
PubMed1996

Transcript map of the human chromosome 4p16.3 consisting of 627 cDNA clones derived from 1 Mb of the Huntington's disease locus.

Six hundred and twenty-seven cDNA clones from human brain cDNA libraries were characterized and integrated into a transcript map of the 1-Mb region on human chromosome 4p16.3 containing the Huntington's disease (HD) gene. Six hundred and seventy-two cDNA clones were obtained by a direct screening of the cDNA libraries, probing with pools of single copy microclones generated from the HD region specific yeast artificial chromosome (YAC)-DNA. So far, 93% of the obtained clones (627 cDNA clones) have been mapped onto the 1-Mb HD gene region by hybridization with HD region-specific cosmid, P1 and YAC clones. DNA sequence and expression analyses revealed that several cDNA clones might encode novel genes, some of which are situated within or close to the IT15, IT11, and alpha-adducin (ADD1) gene region, suggesting the presence of the overlapping genes in this region. This collection of cDNA clones will greatly facilitate the construction of the complete map of the transcripts in the HD region.

Animals↗
PubMed1992

BsuBI--an isospecific restriction and modification system of PstI: characterization of the BsuBI genes and enzymes.

The enzymes of the Bacillus subtilis BsuBI restriction/modification (R/M) system recognize the target sequence 5'CTGCAG. The genes of the BsuBI R/M system have been cloned and sequenced and their products have been characterized following overexpression and purification. The gene of the BsuBI DNA methyltransferase (M.BsuBI) consists of 1503 bp, encoding a protein of 501 amino acids with a calculated M(r) of 57.2 kD. The gene of the restriction endonuclease (R.BsuBI), comprising 948 bp, codes for a protein of 316 amino acids with a predicted M(r) of 36.2 kD. M.BsuBI modifies the adenine (A) residue of the BsuBI target site, thus representing the first A-N6-DNA methyltransferase identified in B. subtilis. Like R.PstI, R.BsuBI cleaves between the A residue and the 3' terminal G of the target site. Both enzymes of the BsuBI R/M system are, therefore, functionally identical with those of the PstI R/M system, encoded by the Gram negative species Providencia stuartii. This functional equivalence coincides with a pronounced similarity of the BsuBI/PstI DNA methyltransferases (41% amino acid identity) and restriction endonucleases (46% amino acid identity). Since the genes are also very similar (58% nucleotide identity), the BsuBI and PstI R/M systems apparently have a common evolutionary origin. In spite of the sequence conservation the gene organization is strikingly different in the two R/M systems. While the genes of the PstI R/M system are separated and transcribed divergently, the genes of the BsuBI R/M system are transcribed in the same direction, with the 3' end of the M gene overlapping the 5' end of the R gene by 17 bp.

Amino Acid Sequence↗
PubMed1994

Homologous pairing proteins encoded by the Escherichia coli recE and recT genes.

Early genetic analysis of alternate recombination pathways in Escherichia coli identified the RecE recombination pathway and the required exonuclease VIII encoded by the recE gene. Observations that not all recombination events promoted by the RecE pathway require recA suggest the existence of an additional homologous pairing protein besides RecA in E. coli. Genetic and biochemical analysis of the recE gene region indicates there are two partially overlapping genes, recE and recT, encoding at least two proteins: exoVIII and the RecT protein. Biochemical analysis has shown that the RecT protein, in combination with exoVIII, promotes homologous pairing and strand exchange in reactions containing linear duplex DNA and homologous, circular, singlestranded DNA as substrates. This reaction occurs in the absence of any high-energy cofactor. These two proteins, RecT and exoVIII, appear to be members of a second class of homologous pairing proteins that are required in genetic recombination and differ from the class of homologous pairing proteins that includes RecA. Members of this second class of proteins appear to include both bacteriophage-encoded proteins and proteins from eukaryotes and their viruses.

Amino Acid Sequence↗