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At least 307 records · Page 17Linked to original sources
PubMed2005

Genetic and physiological analysis of the major OxyR-regulated katA from Xanthomonas campestris pv. phaseoli.

katA encodes the major catalase that accounts for 90 % of the total catalase activity present in Xanthomonas campestris pv. phaseoli. katA is located upstream of an ORF designated ankA encoding a cytoplasmic membrane protein homologous to eukaryotic ankyrin. Transcriptional analysis of katA and ankA identified two katA transcripts: a major monocistronic katA transcript and a minor bicistronic katA-ankA transcript. KatA expression was induced in the presence of various oxidants including H2O2, organic hydroperoxides and the superoxide-generating agent menadione, in an OxyR-dependent manner. Analysis of the katA promoter region showed a putative OxyR binding site located upstream of an Escherichia coli-like sigma70 -35 region that is likely to be responsible for transcription activation in response to oxidant treatment. Gel mobility shift experiments confirmed that purified OxyR specifically binds to the katA promoter. A katA mutant was highly sensitive to H2O2 during both the exponential and stationary phases of growth. This phenotype could be complemented by functional katA, confirming the essential role of the gene in protecting X. campestris from H2O2 toxicity. Unexpectedly, inactivation of ankA also significantly reduced resistance to H2O2 and the phenotype could be complemented by plasmid-borne expression of ankA. Physiological analyses showed that katA plays an important role in, but is not solely responsible for, both the adaptive and menadione-induced cross-protective responses to H2O2 killing in X. campestris.

Ankyrins↗
PubMed1997

Identification and transcriptional analysis of a Treponema pallidum operon encoding a putative ABC transport system, an iron-activated repressor protein homolog, and a glycolytic pathway enzyme homolog.

We have characterized a 5.2-kilobase (kb) putative transport related operon (tro) locus of Treponema pallidum subsp. pallidum (Nichols strain) (Tp) encoding six proteins: TroA, TroB, TroC, TroD, TroR and Phosphoglycerate mutase (Pgm). Four of these gene products (TroA-TroD) are homologous to members of the ATP-Binding Cassette (ABC) superfamily of bacterial transport proteins. TroA (previously identified as Tromp1) has significant sequence similarity to a family of Gram-negative periplasmic substrate-binding proteins and to a family of streptococcal proteins that may have dual roles as substrate binding proteins and adhesins. TroB is homologous to the ATP-binding protein component, whereas TroC and TroD are related to the hydrophobic membrane protein components of ABC transport systems. TroR is similar to Gram-positive iron-activated repressor proteins (DesR, DtxR, IdeR, and SirR). The last open reading frame (ORF) of the tro operon encodes a protein that is highly homologous to the glycolytic pathway enzyme, Pgm. Primer extension results demonstrated that the tro operon is transcribed from a sigma 70-type promoter element. Northern analysis and reverse transcriptase-polymerase chain reactions provided evidence for the presence of a primary 1-kb troA transcript and a secondary, less abundant, troA-pgm transcript. The tro operon is flanked by a Holliday structure DNA helicase homolog (upstream) and two ORFs representing a purine nucleoside phosphorylase homolog and tpp15, a previously characterized gene encoding a membrane lipoprotein (downstream). The presence of a complex operon containing a putative ABC transport system and a DtxR homolog indicates a possible linkage between transport and gene regulation in Tp.

ATP-Binding Cassette Transporters↗
PubMed2001

Glycosylation with heptose residues mediated by the aah gene product is essential for adherence of the AIDA-I adhesin.

The diffuse adherence of Escherichia coli strain 2787 (O126:H27) is mediated by the autotransporter adhesin AIDA-I (adhesin-involved-in-diffuse-adherence) encoded by the plasmid-borne aidA gene. AIDA-I exhibits an aberrant mobility in denaturing gel electrophoresis. Deletion of the open reading frame (ORF) A immediately upstream of aidA restores the predicted mobility of AIDA-I, but the adhesin is no longer functional. This indicates that the mature AIDA-I adhesin is post-translationally modified and the modification is essential for adherence function. Labelling with digoxigenin hydrazide shows AIDA-I to be glycosylated. Using carbohydrate composition analysis, AIDA-I contains exclusively heptose residues (ratio heptose:AIDA-I approximately 19:1). The deduced amino acid sequence of the cytoplasmic open reading frame (ORF) A gene product shows homologies to heptosyltransferases. In addition, the modification was completely abolished in an ADP-glycero-manno-heptopyranose mutant. Our results provide direct evidence for glycosylation of the AIDA-I adhesin by heptoses with the ORF A gene product as a specific (mono)heptosyltransferase generating the functional mature AIDA-I adhesin. Consequently, the ORF A gene has been denoted 'aah' (autotransporter-adhesin-heptosyltransferase). Glycosylation by heptoses represents a novel protein modification in eubacteria.

Adhesins, Escherichia coli↗
PubMed1991

Functional analysis of human cytomegalovirus morphological transforming region II (mtrII).

Human cytomegalovirus (HCMV) transforming region II (mtrII), a 980-bp sequence, can transform rodent fibroblasts. This region contains three small potential open reading frames (ORFs) of 79, 83, and 34 amino acid residues. To identify the specific role of mtrII sequences in transformation, we investigated (1) the presence of mtrII DNA and mtrII-specific RNA transcripts in NIH 3T3 transformants and their tumor derivatives, and (2) the ability of mtrII DNA and its subregions to cis-activate chloramphenicol acetyl transferase (CAT) gene expression. By hybridization analysis, mtrII-specific DNA and RNA were detected in both transformed and tumor cells. A 285-bp sequence upstream of the ORFs in mtrII exhibited weak promoter activity when linked to CAT gene in the sense orientation with respect to the ORFs. Promoter activity of this region was stronger than the enhancer activity in the sense orientation. No promoter or enhancer activity was detected in the antisense orientation. The mtrII 980-bp sequence did not exhibit any promoter activity in either orientation. These results suggested that HCMV mtrII may contain a small transforming gene that may be transcribed at low levels from its own promoter.

Animals↗
PubMed1997

Genetically variable triplet repeats in a RING-finger ORF of Helicoverpa species baculoviruses.

Nucleotide sequence analysis of the Helicoverpa zea S-type nucleopolyhedrovirus (HzSNPV) genomic interval between the polh and iel genes has revealed an open reading frame (HOAR ORF) that contains a complex A 1-T rich triplet repeat region (RAT-repeats). HOAR ORF is predicted to encode an acidic, arginine residue rich. 712 aa protein, with a C3HC4 (RING-finger) zinc binding motif. RAT-repeats, distributed over 450 bp. consist of GAT. AAT, and GTT codons, correspond to Asp, Asn and Val residues which display an extreme codon bias not seen with nine other genes of this virus. A survey of four other (field) isolates of Helicoverpa sp. NPVs confirms a high incidence of mutation in the RAT-repeat region. A 158-bp conserved block, homologous to the pe38-ien promoter of AcMNPV, was identified upstream of HOAR ORF. The sub-region of the genome in which HOAR ORF is located is susceptible to rearrangement.

Amino Acid Sequence↗
PubMed2004

Characterization of Trypanosoma cruzi TcRjl locus and analysis of its transcript.

RJLs represent a recently described family of the Ras-related GTP-binding proteins. The Trypanosoma cruzi orthologue, TeRjl, was isolated and its locus was characterized in a region of almost 5 kb. Its 660 bp orf, predicting a protein of 24.13 kDa, is present as a single copy gene in T. cruzi I lineage, and from 1-2 copies in T. cruzi II lineage. TcRjl shares 73% aa sequence similarity with its closest identified orthologue, T. brucei TbRjl. RT-PCR experiments revealed that TcRjl is transcribed in mRNA in the 3 main life forms of the parasite, while Northern hybridization demonstrated that TcRjl is transcribed in T. cruzi epimastigotes as at least 2 transcripts, one of around 950 nt and the other of 1500 nt. Splice-leader addition was mapped to a single site at -69 bp upstream of TcRjl orf indicating that the two mRNA types may derive in differences at the 3' of TcRjl mRNA. TcRjl locus presents considerable synteny with Rjl loci from Trypanosoma brucei and Leishmania major as available from their respective genome projects.

Amino Acid Sequence↗
PubMed1989

Cloning and sequencing of the gene encoding a 125-kilodalton surface-layer protein from Bacillus sphaericus 2362 and of a related cryptic gene.

Using the vector pGEM-4-blue, a 4,251-base-pair DNA fragment containing the gene for the surface (S)-layer protein of Bacillus sphaericus 2362 was cloned into Escherichia coli. Determination of the nucleotide sequence indicated an open reading frame (ORF) coding for a protein of 1,176 amino acids with a molecular size of 125 kilodaltons (kDa). A protein of this size which reacted with antibody to the 122-kDa S-layer protein of B. sphaericus was detected in cells of E. coli containing the recombinant plasmid. Analysis of the deduced amino acid sequence indicated a highly hydrophobic N-terminal region which had the characteristics of a leader peptide. The first amino acid of the N-terminal sequence of the 122-kDa S-layer protein followed the predicted cleavage site of the leader peptide in the 125-kDa protein. A sequence characteristic of promoters expressed during vegetative growth was found within a 177-base-pair region upstream from the ORF coding for the 125-kDa protein. This putative promoter may account for the expression of this gene during the vegetative growth of B. sphaericus and E. coli. The gene for the 125-kDa protein was followed by an inverted repeat characteristic of terminators. Downstream from this gene (11.2 kilobases) was an ORF coding for a putative 80-kDa protein having a high sequence similarity to the 125-kDa protein. Evidence was presented indicating that this gene is cryptic.

Amino Acid Sequence↗
PubMed2004

The DNA beta satellite component associated with ageratum yellow vein disease encodes an essential pathogenicity protein (betaC1).

Ageratum yellow vein disease (AYVD) is caused by the geminivirus ageratum yellow vein virus (AYVV) and an associated DNA beta satellite. We have mapped a DNA beta transcript to a highly conserved open reading frame (betaC1 ORF). The most abundant transcript 5'-terminus is located 8 bases upstream of the betaC1 ORF putative initiation codon while the transcript terminates at multiple sites downstream from the putative termination codon. Disruption of betaC1 protein expression by the introduction of an internal nonsense codon prevented infection of the AYVV-satellite complex in ageratum and altered the phenotype in Nicotiana benthamiana to that produced by AYVV alone although the mutant was maintained in systemically infected tissues. Modification of the putative initiation codon to a nonsense codon produced an intermediate phenotype in N. benthamiana and a mild yellow vein phenotype in ageratum, suggesting that betaC1 protein expression could be initiated from an alternative site. N. benthamiana plants containing a dimeric DNA beta transgene produced severe developmental abnormalities, vein-greening, and cell proliferation in the vascular bundles. Expression of betaC1 protein from a potato virus X (PVX) vector also induced abnormal plant growth. Our results demonstrate that the satellite encodes at least one protein that plays a major role in symptom development and is essential for disease progression in ageratum, the natural host of the AYVD complex.

Ageratum↗
PubMed1996

The genes encoding the P39 and CG30 proteins of Bombyx mori nuclear polyhedrosis virus.

We have cloned and analysed the transcriptional properties of two closely linked genes, p39 and cg30, of Bombyx mori nuclear polyhedrosis virus (BmNPV). These genes encode a structural polypeptide and a putative transcriptional regulator of the virus, respectively. The cg30 gene is transcribed prior to and after DNA replication from a site located within the ORF of the adjacent p39 gene. Its transcription product, a 1.3 kb mRNA, is polyadenylated at a site containing consensus eukaryotic polyadenylation signals and mapping 87 bp downstream of the translation termination codon for CG30. During the later stages of infection, two additional RNAs, 2.2 and 6.5 kb, are also transcribed through the cg30 gene. The 2.2 kb RNA, representing the mRNA that encodes P39, is initiated from three relatively closely spaced sites located upstream of the P39 ORF. The 6.5 kb RNA is apparently transcribed from the promoter sequences of another gene located further upstream of the p39 gene. The 2.2 and 6.5 kb transcripts have two polyadenylation sites. The first site is the same as the one used to generate the cg30 gene-specific transcripts. The second is located 4 bp downstream of the CG30 translation termination codon. Transient expression assays show that the p39 gene sequences immediately upstream of the CG30 ORF can direct expression of a reporter gene when the latter is co-transfected with the gene encoding the early baculovirus trans-activator IE1. Thus, these sequences behave as a delayed-early baculovirus gene promoter.

Amino Acid Sequence↗
PubMed1994

Genetic and nucleotide sequence analysis of the gene htdA, which regulates conjugal transfer of IncHI plasmids.

IncHI plasmids are naturally repressed for conjugative transfer and do not allow efficient propagation of the IncH pilus-specific phage Hgal. Transposons Tn7, Tn5, and TnlacZ were inserted into IncHI plasmids R478, R477-1, and R27, respectively, leading to the isolation of several plasmid mutants which exhibited increased levels of transfer and also permitted good lysis with phage Hgal. A 4.3-kb HindIII fragment from R478 reversed both phenotypic effects of derepression for the R477-1::Tn5 and the R478::Tn7 derivatives, pKFW99 and pKFW100, respectively. Exonuclease III deletions of this fragment and nucleotide sequence analysis indicated that the gene responsible for transfer repression, named here htdA, encoded a polypeptide of 150 amino acids. Cloning and sequence analysis of pDT2454 (R27::TnlacZ) revealed that the transposon had inserted into an open reading frame (ORF) which had an 83% amino acid identity with the R478 htdA gene. Maxicell analysis showed both the R27 and R478 HtdA products had molecular masses of 19.9 kDa. Conjugation experiments showed that the cloned htdA determinants caused a significant reduction of the transfer frequencies of wild-type R478 and R27 plasmids. Examination of both R478 derepressed mutants, pKFW100 and pKFW101, indicated that both transposon insertions occurred upstream of the htdA ORF. The results suggest that HtdA is a regulatory component of IncH plasmid transfer and also show that the region upstream of the htdA ORF is involved in transfer repression. The locations of the htdA determinants were identified on the plasmid maps of R27 and R478.

Amino Acid Sequence↗
PubMed1994

Low-incidence latent infection with variant B or roseola type human herpesvirus 6 in leukocytes of healthy adults.

Nested primer-based polymerase chain reaction was employed to determine the frequency of latent infection with human herpesvirus 6 (HHV-6) among healthy adults from Bratislava, Slovak Republic. A 592-bp region, upstream from the gene encoding the putative large tegument protein of HHV-6, was amplified from DNA extracted from peripheral blood mononuclear cells (PBMC) of only one of 29 seropositive adults, suggesting that as few as 1 in 10(5) PBMC may be infected with the virus. Direct sequencing of the 592-bp fragment indicated that the virus harbored by the seropositive Slovak subject (designated B38) differed by only 3 nucleotides from an HHV-6 variant B strain (R-147) isolated from an American infant with a roseola-like illness and by 32 bases from the variant A strain GS isolated from a patient with lymphadenopathy (5.4% sequence divergence). None of these strains had a deoxyadenosine at base position 1251, when compared to the published sequence of strain GS clone pZVH14. Although this discrepancy did not affect the large tegument protein gene, it altered the predicted amino acid sequences of two putative proteins coded by open-reading frames 1 and 2 (ORF 1 and ORF 2) located upstream from this gene.

Adult↗
PubMed2004

A stable upstream stem-loop structure enhances selection of the first 5'-ORF-AUG as a main start codon for translation initiation of human ACAT1 mRNA.

Human ACAT 1 cDNA K1 was first cloned and functionally expressed in 1993. There are two adjacent in-frame AUG codons, AUG(1397-1399) and AUG(1415-1417), at 5'-terminus of the open reading frame (ORF, nt 1397-3049) of human ACAT1 mRNA corresponding to cDNA K1. In current work, these two adjacent inframe AUGs at 5'-terminus of the predicted ORF (5'-ORF-AUGs) as start codons for translation initiation of human ACAT1 mRNA were characterized in detail. Codon mutations indicated that both of these two adjacent 5'-ORF-AUGs can be selected as start codons but the first 5'-ORF-AUG(1397-1399) is a main start codon consistent with that of the predicted ORF of human ACAT1 mRNA. Further deletion and mutation analyses demonstrated that a stable upstream stem-loop structure enhanced the selection of the first 5'-ORF-AUG(1397 -1399) as a main start codon, in addition to upstream nucleotide A in the -3 position, which is a key site of Kozak sequence. In addition, result of ACAT1 enzymatic activity assay showed no obvious difference between these two ACAT1 proteins respectively initiated from the two adjacent 5'-ORF-AUGs. This work showed that a stable upstream stem-loop structure could modulate the start codon selection during translation initiation of mRNAs that contain adjacent multi-5'-ORF-AUGs.

5' Untranslated Regions↗
PubMed1994

Cloning and expression in Escherichia coli of a Streptomyces coelicolor A3(2) argCJB gene cluster.

From a partial Sau3AI library of Streptomyces coelicolor A3(2) DNA in pIJ916, two hybrid plasmids pGX1 and pGX2 were isolated that complemented S. coelicolor A3(2) or S. lividans arginine auxotrophs. Subcloning DNA from pGX1 in the Escherichia coli expression vector pRK9 containing the Serratia marcescens trp promoter gave rise to one plasmid, pZC2, that complemented E. coli argB, C, E and H auxotrophs, and another, pZC1, that complemented only the first three. The plasmids were markedly unstable in the various complemented hosts, to varying extents; pZC1 was characterized further as providing the stablest host/plasmid combinations. In vitro deletion of part of the vector's trp promoter did not affect complementation of the argB and C auxotrophs, implying that the S. coelicolor A3(2) arg genes may be expressed from their own promoter. The trp promoter-less plasmids included isolates, such as pZC177, that had suffered extensive further deletion without loss of complementing ability. Extracts of an E. coli argE auxotroph carrying pZC177 showed ornithine acetyltransferase activity, indicating that the complementing gene is of the argJ type. The complementation properties of in vitro deletion derivatives of pZC177 indicated the gene order argC-J-B. Part of argC and the upstream region were sequenced; an ORF was identified whose predicted product showed appreciable homology with the E. coli and Bacillus subtilis ArgC polypeptide. Upstream of this ORF a consensus-type promoter and ribosome binding site could be discerned; overlapping its promoter was a sequence with homology to arginine operators in these two other organisms.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetyltransferases↗
PubMed2000

Sequence analysis and modular organization of threonyl-tRNA synthetase from Thermus thermophilus and its interrelation with threonyl-tRNA synthetases of other origins.

The gene encoding threonyl-tRNA synthetase (Thr-tRNA synthetase) from the extreme thermophilic eubacterium Thermus thermophilus HB8 has been cloned and sequenced. The ORF encodes a polypeptide chain of 659 amino acids (Mr 75 550) that shares strong similarities with other Thr-tRNA synthetases. Comparative analysis with the three-dimensional structure of other subclass IIa synthetases shows it to be organized into four structural modules: two N-terminal modules specific to Thr-tRNA synthetases, a catalytic core and a C-terminal anticodon-binding module. Comparison with the three-dimensional structure of Escherichia coli Thr-tRNA synthetase in complex with tRNAThr enabled identification of the residues involved in substrate binding and catalytic activity. Analysis by atomic absorption spectrometry of the enzyme overexpressed in E. coli revealed the presence in each monomer of one tightly bound zinc atom, which is essential for activity. Despite strong similarites in modular organization, Thr-tRNA synthetases diverge from other subclass IIa synthetases on the basis of their N-terminal extensions. The eubacterial and eukaryotic enzymes possess a large extension folded into two structural domains, N1 and N2, that are not significantly similar to the shorter extension of the archaebacterial enzymes. Investigation of a truncated Thr-tRNA synthetase demonstrated that domain N1 is not essential for tRNA charging. Thr-tRNA synthetase from T. thermophilus is of the eubacterial type, in contrast to other synthetases from this organism, which exhibit archaebacterial characteristics. Alignments show conservation of part of domain N2 in the C-terminal moiety of Ala-tRNA synthetases. Analysis of the nucleotide sequence upstream from the ORF showed the absence of both any anticodon-like stem-loop structure and a loop containing sequences complementary to the anticodon and the CCA end of tRNAThr. This means that the expression of Thr-tRNA synthetase in T. thermophilus is not regulated by the translational and trancriptional mechanisms described for E. coli thrS and Bacillus subtilis thrS and thrZ. Here we discuss our results in the context of evolution of the threonylation systems and of the position of T. thermophilus in the phylogenic tree.

Amino Acid Motifs↗
PubMed1995

Genetic analysis of the minimal replicon of plasmid pIP417 and comparison with the other encoding 5-nitroimidazole resistance plasmids from Bacteroides spp.

The nucleotide sequence of the DNA replication origin region of a Bacteroides vulgatus plasmid, pIP417, encoding 5-nitroimidazole resistance has been determined. This region of 1934 bp presents some characteristics similar to those of other replication protein-dependent origins. It contains a large open reading frame which could encode a basic Rep protein (RepA) of 36.8 kDa. Upstream of this ORF exist an AT-rich region, three direct repeats (iterons) of 21 bp, multiple DnaA binding sites, and sites, and sites for the integration host factor (IHF). Moreover, the amino acid sequence of the pIP417 RepA protein shows similarities with those of other Rep proteins encoded by plasmids of gram-negative bacteria: pRO1600 from Pseudomonas aeruginosa; pPS10 from Pseudomonas syringae; pFA3 from Neisseria gonorrhoeae; and two cryptic plasmids from Campylobacter hyointestinalis and Butyrivibrio fibrisolvens. Although RepA can be expressed in an Escherichia coli in vitro transcription-translation assay, vectors containing the pIP417 replication origin did not replicate in E. coli. The homology of the pIP417 replication region with the corresponding regions of other Bacteroides spp, plasmids was also studied by Southern blot hybridization. The results indicated that the repA gene of plasmid pIP417 is homologous to that of plasmid pIP421, but not of plasmid pIP419. The replication region of plasmid pIP421 was sequenced and showed about 80% identity at the nucleotide level with that of pIP417. A small (3634-bp) cloning vector (pFK12) of entirely defined nucleotide sequence was constructed for Bacteroides spp.

Amino Acid Sequence↗
PubMed1997

Identification of plasmids in the genus Marinococcus and complete nucleotide sequence of plasmid pPL1 from Marinococcus halophilus.

Several plasmids were detected in the Gram-positive halophilic eubacterium Marinococcus halophilus and in the related strain M52. The complete nucleotide sequence (3874 bp) of one of these plasmids, pPL1, was determined. Four major open reading frames were identified. Whereas orf3 and orf4 showed no sequence similarities to known proteins, rep displayed a high sequence similarity to replication proteins of rolling circle plasmids. Upstream of this ORF, a sequence resembling the double-strand origin was detected. A region probably constituting the single-strand origin was identified. The ORF mob showed sequence similarity with Mob proteins of rolling circle plasmids. The observed characteristics suggest that pPL1 replicates according to the rolling circle mechanism.

Amino Acid Sequence↗
PubMed1993

A baculovirus encoded 16-kDa glycoprotein localizes near the nuclear membrane of infected cells.

An open reading frame (ORF 2) located upstream of the polyhedron envelope protein gene of Orgyia pseudotsugata multicapsid nuclear polyhedrosis virus (OpMNPV) was cloned in frame into a trpE expression vector. The fusion protein produced by this construct was used for the production of a monospecific antiserum. Western blot analysis of OpMNPV-infected Lymantria dispar cells detected a 16-kDa protein at 24 hr postinfection. The 16-kDa protein was determined to be N-glycosylated by tunicamycin treatment of infected cells. Immunofluorescence microscopy localized the 16-kDa protein to foci of intense cytoplasmic staining near the nuclear membrane. Immunoelectron microscopy indicated that the 16-kDa protein is associated with lamellar-like structures peripheral to the nuclear membrane and with envelopes of virus that have budded into the cytoplasm. The 16-kDa protein was not associated with extracellular budded or polyhedron-derived virions.

Animals↗
PubMed1995

Complete sequence (20 kilobases) of the polyprotein-encoding gene 1 of transmissible gastroenteritis virus.

The entire nucleotide sequence of cloned cDNAs containing the 5'-untranslated region and gene 1 of Purdue-115 strain of transmissible gastroenteritis virus (TGEV) was determined. This completes the sequence of the TGEV genome, which is 28,579 nucleotides long. The gene 1 is composed of two large open reading frames, ORF1a and ORF1b, which contain 4017 and 2698 codons, respectively (stop excluded). A brief, three-codon-long ORF is present upstream of ORF1a. ORF1b overlaps ORF1a by 43 bases in the (-1) reading frame. In vitro experiments indicated that translation of the ORF1a/b polyprotein involves an efficient ribosomal frameshifting activity, as previously shown for other coronaviruses. Analysis of the predicted ORF1a and ORF1b translation products revealed that the putative functional domains identified in infectious bronchitis virus (IBV), mouse hepatitis virus (MHV) and human coronavirus 229E (HCV 229E) are all present in TGEV. The amino-terminal half of the ORF1a product exhibits greater divergence than the carboxyl-terminal half, including within the TGEV/HCV229E pair. The ORF1b protein is overall highly conserved among the above four coronaviruses, except a divergent region situated near the carboxy terminus.

Amino Acid Sequence↗