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Query: UMLS:C0149514 (
bronchitis
)
6,902
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The 5'-most gene, gene 1, of the genome of murine coronavirus, mouse hepatitis virus (MHV), is presumed to encode the viral RNA-dependent RNA polymerase. We have determined the complete sequence of this gene of the JHM strain by cDNA cloning and sequencing. The total length of this gene is 21,798 nucleotides long, which includes two overlapping, large open reading frames. The first open reading frame,
ORF
1a, is 4488 amino acids long. The second open reading frame,
ORF
1b, overlaps
ORF
1a for 75 nucleotides, and is 2731 amino acids long. The overlapping region may fold into a pseudoknot RNA structure, similar to the corresponding region of the RNA of avian coronavirus, infectious
bronchitis
virus (IBV). The in vitro transcription and translation studies of this region indicated that these two ORFs were most likely translated into one polyprotein by a ribosomal frameshifting mechanism. Thus, the predicted molecular weight of the gene 1 product is more than 800,000 Da. The sequence of
ORF
1b is very similar to the corresponding
ORF
of IBV. In contrast, the
ORF
1a of these two viruses differ in size and have a high degree of divergence. The amino acid sequence analysis suggested that
ORF
1a contains several functional domains, including two hydrophobic, membrane-anchoring domains, and three cysteine-rich domains. It also contains a picornaviral 3C-like protease domain and two papain-like protease domains. The presence of these protease domains suggests that the polyprotein is most likely processed into multiple protein products. In contrast, the
ORF
1b contains polymerase, helicase, and zinc-finger motifs. These sequence studies suggested that the MHV gene 1 product is involved in RNA synthesis, and that this product is processed autoproteolytically after translation. This study completes the sequence of the MHV genome, which is 31 kb long, and constitutes the largest viral RNA known.
...
PMID:The complete sequence (22 kilobases) of murine coronavirus gene 1 encoding the putative proteases and RNA polymerase. 184 89
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.
...
PMID:Complete sequence (20 kilobases) of the polyprotein-encoding gene 1 of transmissible gastroenteritis virus. 785 95
The sequence of the HCV 229E gene 1 has been determined and compared with the homologous sequences of the murine hepatitis virus and the avian infectious
bronchitis
virus. The coding sequence of gene 1 is 20,273 nucleotides in length. Within this coding region are two large open reading frames,
ORF
1a (4,086 codons) and
ORF
1b (2,687 codons) which overlap by 40 nucleotides. In the overlapping region, the genomic RNA can be folded into a pseudoknot structure, an element which is known to mediate -1 ribosomal frame-shifting in other coronaviruses. Assuming that -1 frame-shifting occurs at the HCV sequence UUUAAAC (nucleotides 12,514-12,520), the
ORF
1a -
ORF
1b product is predicted to be 6,758 amino acids in length. Our sequence analysis of the HCV 229E gene 1 has revealed a high degree of similarity within the
ORF
1b of HCV, MHV and IBV, whereas
ORF
1a is much less conserved. Elements which are believed to be necessary for specific (e.g. frame-shifting) and general (e.g. NTP-binding/helicase) transcriptional functions have been identified. This study completes the genomic sequence of HCV 229E which is 27.27 kb long and one of the largest known RNA genomes.
...
PMID:Characterization of the human coronavirus 229E (HCV 229E) gene 1. 820 74
In a previous report, we showed that proteolytic processing of an 87-kDa mature viral protein from the coronavirus infectious
bronchitis
virus (IBV) 1a and 1a/1b polyproteins was mediated by two putative overlapping papain-like proteinase domains (PLPDs) encoded within the region from nucleotides 4243 to 5553 of
ORF
1a (Liu et al., 1995). In this study, we demonstrate that only the first domain, PLPD-1, is responsible for this cleavage, as deletion of the second domain did not affect the formation of the 87-kDa protein. Site-directed mutagenesis studies further showed that a previously predicted nucleophilic cysteine residue (Cys1274) and a histidine residue (His1437) were essential for the proteinase activity, indicating that they may be important components of the catalytic center of the proteinase. Meanwhile, expression of a series of deletion mutants revealed that the 87-kDa protein was encoded by the 5'-most 2.6 kb of
ORF
1a. Deletion and amino acid substitution mutation studies demonstrated that the Gly673-Gly674 dipeptide bond was most likely the cleavage site responsible for releasing the C-terminus of the 87-kDa protein from the 1a and 1a/1b polyproteins.
...
PMID:Characterization of the two overlapping papain-like proteinase domains encoded in gene 1 of the coronavirus infectious bronchitis virus and determination of the C-terminal cleavage site of an 87-kDa protein. 963 69
We have previously reported that the 3C-like proteinase of the coronavirus infectious
bronchitis
virus (IBV) is responsible for processing of the 1a and 1a/1b polyproteins to three mature products of 24, 10, and 100 kDa (Liu et al., 1994, 1997; Ng and Liu, 1998). The C-terminal cleavage site of the 100-kDa protein was defined to be the Q891(1b)-S892(1b) dipeptide bond encoded by nucleotides 15,129 to 15,134 (Liu and Brown, 1995). In this report, other cleavage sites of the 3C-like proteinase in the polyprotein encoded by the
ORF
1b region were mapped by coexpression, deletion, and site-directed mutagenesis studies. Using two
ORF
1b-specific antisera, V58 and V17, three more Q-S(G) dipeptide bonds, encoded by nucleotides 16,929 to 16,934, 18,492 to 18,497, and 19,506 to 19,511, respectively, were demonstrated to be the cleavage sites of the 3C-like proteinase. Cleavage at these four positions would result in the release of four mature products with molecular masses of approximately 68, 58, 39, and 35 kDa. Among them, the 39- and 35-kDa proteins were specifically identified in IBV-infected cells. Taken together with the 100-kDa protein previously identified, these results suggest that the
ORF
1b region of IBV mRNA1 may be able to encode five mature products.
...
PMID:Proteolytic mapping of the coronavirus infectious bronchitis virus 1b polyprotein: evidence for the presence of four cleavage sites of the 3C-like proteinase and identification of two novel cleavage products. 965 47
The defective RNA (D-RNA) CD-61, derived from the Beaudette strain of the avian coronavirus infectious
bronchitis
virus (IBV), was used as an RNA vector for the expression of two reporter genes, luciferase and chloramphenicol acetyltransferase (CAT). D-RNAs expressing the CAT gene were demonstrated to be capable of producing CAT protein in a helper-dependent expression system to about 1.6 microgram per 10(6) cells. The reporter genes were expressed from two different sites within the CD-61 sequence and expression was not affected by interruption of the CD-61-specific
ORF
. Expression of the reporter genes was under the control of a transcription-associated sequence (TAS) derived from the Beaudette gene 5, normally used for the transcription of IBV subgenomic mRNA 5. The Beaudette gene 5 TAS is composed of two tandem repeats of the IBV canonical consensus sequence involved in the acquisition of a leader sequence during the discontinuous transcription of IBV subgenomic mRNAs. It is demonstrated that only one canonical sequence is required for expression of mRNA 5 or for the expression of an mRNA from a D-RNA and that either sequence can function as an acceptor site for acquisition of the leader sequence.
...
PMID:Expression of reporter genes from the defective RNA CD-61 of the coronavirus infectious bronchitis virus. 1085 73
Coronavirus infectious
bronchitis
virus (IBV) encodes a trypsin-like proteinase (3C-like proteinase) by
ORF
1a, which has been demonstrated to play a pivotal role in proteolytic processing of gene 1-encoded polyproteins. In our previous studies, the proteinase was identified as a 33-kDa protein in IBV-infected cells, and its catalytic center was shown to consist of H(2820) and C(2922) residues. It is released from the 1a and 1a/1b polyproteins by autoprocessing at two Q-S dipeptide bonds (Q(2779)-S(2780) and Q(3086)-S(3087)). In this report, further characterization of the two cleavage sites demonstrates that the N-terminal Q(2779)-S(2780) site is tolerant to mutations at the P1 position. Deletion of the C-terminal region of the proteinase shows that a significant amount of the enzymatic activity is maintained upon deletion of up to 67 amino acids, suggesting that the extreme C-terminal region may be dispensable for the proteolytic activity of the proteinase. Analysis of the autoprocessing kinetics in vitro reveals that proteolysis at the Q(2779)-S(2780) site is the first cleavage event mediated by this proteinase. This is followed by cleavage at the Q(3086)-S(3087) site. The occurrence of both cleavage events in intact cells is potentially rapid and efficient, as no intermediate cleavage products covering the proteinase were detected in either IBV-infected or transfected cells. Immunofluorescence microscopy and subcellular fractionation studies further show differential subcellular localization of the proteinase in IBV-infected cells and in cells expressing the 3C-like proteinase alone, indicating that additional roles in viral replication might be played by this protein. Finally, a Q-A (Q(3379)-A(3380)) dipeptide bond encoded by nucleotides 10,663 to 10,668 was demonstrated to be a cleavage site of the proteinase.
...
PMID:Further characterization of the coronavirus infectious bronchitis virus 3C-like proteinase and determination of a new cleavage site. 1087 46
Turkey coronavirus (TCoV), one of the least characterized of all known coronaviruses, was isolated from an outbreak of acute enteritis in young turkeys in Ontario, Canada, and the full-length genomic sequence was determined. The full-length genome was 27,632 nucleotides plus the 3' poly(A) tail. Two open reading frames, ORFs 1a and 1b, resided in the first two thirds of the genome, and nine additional downstream ORFs were identified. A gene for hemagglutinin-esterase was absent in TCoV. The region between the membrane (M) and nucleocapsid (N) protein genes contained three potential small ORFs:
ORF
-X, a previously uncharacterized
ORF
with an associated putative TRS within the M gene (apparently shared among all group III coronaviruses), and previously described ORFs 5a and 5b. The TCoV genome is organized as follows: 5' UTR--replicase (ORFs 1a, 1b)--spike (S) protein--ORF3 (ORFs 3a, 3b)--small envelop (E or 3c) protein--membrane (M) protein--ORF5 (ORFs X, 5a, 5b)--nucleocapsid (N) protein--3' UTR--poly(A). TCoV genome structure and sequence was most similar, but distinct from, avian infectious
bronchitis
virus (IBV). This is the first complete genome sequence for a TCoV and confirms that TCoV belongs to group III coronaviruses.
...
PMID:Complete genomic sequence of turkey coronavirus. 1846 11
An infectious cDNA clone of H120 vaccine strain of infectious
bronchitis
virus (IBV) was constructed to demonstrate its potential as a gene transfer vector. Primers were designed according to the published genome sequence of H120 strain, and ten cDNA fragments covering the entire genome of H120 strain was amplified by RT-PCR. All the PCR products were ligated into pMD19-T vector and sequenced, and the ORF5a open reading frame in the pMDTM9 plasmid was replaced by an enhanced green fluorescent protein (EGFP) gene. Recombinant plasmids were digested by the restriction enzyme Bsa I, and all the cDNA fragments were recovered. By using appropriate ligation strategy, the genomic cDNA of H120 strain were reconstituted. Then genome RNA was synthesized in vitro by T7 RNA polymerase and transfected into BHK-21 cells. Recombinant virus expressing the green fluorescent protein was rescued and identified by RT-PCR and sequencing. The characteristics of recombinant virus were evaluated by passage in embryonated chicken eggs. This study showed that the 5a
ORF
is a good candidate for an insertion site of recombinant genes for the development of IBV infectious cDNA clone as a gene transfer vector.
...
PMID:[Expression of green fluorescent protein using an infectious cDNA clone of infectious bronchitis virus]. 2146 1
The genome of CK/CH/SD09/005, an isolate of infectious
bronchitis
virus (IBV), was characterized to enable the further understanding of the epidemiology and evolution of IBV in China. Twenty-five pairs of primers were designed to amplify the full-length genome of CK/CH/SD09/005. The nucleotide sequence of CK/CH/SD09/005 was compared with reference IBV strains retrieved from GenBank. The phylogenic relationship between CK/CH/SD09/005 and the reference strains was analyzed based on S1 gene sequences. The complete genome of CK/CH/SD09/005 consisted of 27691 nucleotides (nt), excluding the 5' cap and 3' poly A tail. The whole-genome of CK/CH/SD09/005 shared 97 - 99% nucleotide sequence homology with the GX-NN09032 strain, which was the only complete genome that was closely related to CK/CH/SD09/005. When compared with all reference strains except GX-NN09032, CK/CH/SD09/005 showed the highest similarity to ck/CH/LDL/091022 and SDIB821/2012 (QX-like) in the replicase gene (Gene 1) and 3'UTR, with a sequence identity rate of 97% and 98%, respectively. However, CK/CH/SD09/005 exhibited lower levels of similarity with ck/CH/LDL/091022 and SDIB821/2012 in S-3a-3b-3c/ E-M-5a-5b-N with a sequence identity of 72% - 90%. CK/CH/SD09/005 showed the highest level of nucleotide identity with Korean strain 1011, and Chinese strains CK/CH/LXJ/02I, DK/CH/HN/ZZ2004 and YX10, in
ORF
3c/E (97%), 5a (96%), 5b (99%) and N (96%), respectively. ORFs 3a, 3b and M of CK/CH/SD09/005 exhibited no more than 90% homology with the reference strains, excluding GX-NN09032. The phylogenic analysis based on the S1 gene revealed that CK/CH/SD09/005 and 39 published strains were classified into seven clades (genotypes). CK/CH/SD09/005 was distributed in clade IV with several isolates collected between 2007 and 2012. CK/CH/SD09/005 showed 66% - 69% and 72% - 81% nucleotide identities with the IBV strains of other six clades in the S1 and S2 subunits, respectively. More over, multiple substitutions were found throughout the entire S gene of CK/CH/SD09/005, while insertions and deletions were located within the S1 gene. These results indicated that CK/CH/SD09/005 is a novel variant that may be derived from the QX-like strains that are prevalent in China. Multiple genetic mechanisms, including recombinations, mutations, insertions and deletions, are likely to have contributed to the emergence of this IBV strain.
...
PMID:[Complete genomic analysis of a novel infectious bronchitis virus isolate]. 2527 84
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