Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.30.1 (S1 nuclease)
 3,660 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nucleotide sequence analysis of a 42-kb region of the vaccinia virus (strain Western Reserve) genome identified a gene with the potential to encode a 35.1-kDa polypeptide with properties of a membrane glycoprotein (Smith et al., J. Gen. Virol. 72, 1349-1376, 1991). The 317 amino acid open reading frame (ORF) has similarity with complement control proteins and a secretory vaccinia virus protein (C28K) which interferes with complement function. The predicted B5R gene product differs from the latter protein in that it contains a C-terminal hydrophobic sequence and may be membrane-associated rather than secretory. Transcriptional mapping by Northern blotting and S1 nuclease protection showed that the gene is transcribed both early and late during infection, with the early RNA start site located 60 bp upstream of the late start site that is present at -9 to -5 bp relative to the ORF. Nevertheless, translation of early and late mRNAs are predicted to produce the same polypeptide. A rabbit antiserum was raised to the predicted external hydrophilic domain of B5R expressed in Escherichia coli and used to immunoprecipitate a M(r) 42 K protein from vaccinia-infected cells. This protein was synthesized throughout infection, with a peak from 6 to 7 hr, and its production was inhibited by tunicamycin but not monensin. Western blotting of proteins from purified extracellular enveloped virus (EEV) or intracellular naked virus with anti-B5R serum showed that this M(r) 42 K protein and two higher molecular weight forms (Mr82 and 87 K) were present only in EEV. Anti-B5R serum inhibited comet formation by the IHD-J strain of virus on RK13 cells. B5R is the third vaccinia gene shown to encode an EEV glycoprotein, the others being the virus hemagglutinin gene, and gene SalL4R which encodes a group of lectin-like glycoproteins of M(r) 22-24 K.
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PMID:A constitutively expressed vaccinia gene encodes a 42-kDa glycoprotein related to complement control factors that forms part of the extracellular virus envelope. 158 49

Using an adenovirus-hepatitis B virus (HBV) recombinant, expression of the HBV surface antigen (HBsAg) genes was examined in various cell lines using S1 nuclease mapping and radioimmunoassay. The steady-state level of the 2.4 kb RNA encoding the large HBsAg was much greater than, or the same as, that of the 2.0 kb RNA, encoding the middle and major HBsAgs, in primate cells, but was negligible in non-primate cells, as is the case in most expression systems. According to the amount of 2.4 kb RNA expressed, cells were classified into three groups: those in which (1) the amount of 2.4 kb RNA was much greater than that of 2.0 kb RNA (HepG2 and JHH-4), (2) the amount of 2.4 kb RNA was the same as that of 2.0 kb (Hul-1, HeLa and other non-hepatic primate cells), and (3) the amount of 2.4 kb RNA was less than one-tenth of that of 2.0 kb RNA (rodent cells). Radioimmunoassay revealed that most HBsAg is located intracellularly in primate cells, but is secreted into the culture medium of rodent cells. The expression of 2.4 kb RNA was unaffected by an inhibitor of DNA synthesis in HepG2 cells, which are of human liver origin, whereas it was strongly inhibited in human non-hepatic HeLa cells.
J Gen Virol 1991 Aug
PMID:Preferential expression of the large hepatitis B virus surface antigen gene by an adenovirus-hepatitis B virus recombinant. 165 85

A-factor (2-isocapryloyl-3R-hydroxymethyl-gamma-butyrolactone) is a microbial hormone controlling streptomycin (Sm) production, Sm resistance and sporulation in Streptomyces griseus. In order to identify A-factor-dependent promoters in the Sm biosynthetic gene cluster, a new promoter-probe plasmid with a low copy number was constructed by using an extremely thermostable malate dehydrogenase gene as the reporter. Of the three promoters in the Sm production region that includes strR, aphD and strB, only the promoter of strR, which codes for a putative regulatory protein, was found to be directly controlled by A-factor. This was also confirmed by S1 nuclease mapping. The region essential for its A-factor-dependence was determined to be located 430-330 base pairs upstream of the transcriptional start point. Increase in the copy number of the strR promoter region did not lead to a corresponding increase in the total promoter activity, probably due to titration of a putative activator which binds to the enhancer-like region and controls the expression of the strR promoter. This putative activator is apparently distinct from the A-factor-receptor protein. The aphD gene, which encodes the major Sm resistance determinant, Sm-6-phosphotransferase, was transcribed mainly by read-through from the A-factor-dependent strR promoter; this accounts for the prompt induction of Sm resistance by A-factor.
Mol Gen Genet 1991 Sep
PMID:Identification of an A-factor-dependent promoter in the streptomycin biosynthetic gene cluster of Streptomyces griseus. 165 4

Within the chromosome of the archaebacterium Sulfolobus sp. B12, a 7.4 kb region was identified which displayed extensive sequence similarities to the 15.5 kb genetic element SSV1 carried by the same strain both as a circular form and as a site-specifically integrated copy. DNA sequence analysis indicated that this 7.4 kb region (designated SSV1intB) represented an SSV1-like element distinguishable from the full-length integrated copy (designated SSV1intA) by extensive deletions and point mutations. The physical organization of DNA sequences of SSV1intB indicated that this element was integrated at the same attP site as previously identified for SSV1intA. A comparison of the DNA sequences at the left attachment sites of SSV1intA and SSV1intB revealed that they both represented very similar putative arginine tRNA genes followed by a 10 bp inverted repeat sequence. S1 nuclease mapping experiments indicated that these tRNA genes are transcribed.
Mol Gen Genet 1990 Mar
PMID:Identification and characterization of a defective SSV1 genome integrated into a tRNA gene in the archaebacterium Sulfolobus sp. B12. 169 36

The termination of transcription in the dnaA gene of E. coli was analyzed using transcriptional fusions to the galactokinase gene, S1 nuclease mapping and quantification of translation products by Western blots. The majority of transcripts originating from dnaA promoters terminated at several positions within a 200 bp region inside the dnaA reading frame.
Mol Gen Genet 1991 Dec
PMID:Transcription termination in the dnaA gene. 176 43

The nucleotide sequence of the RNA genome of foxtail mosaic virus (FMV), a member of the potexvirus family, is 6151 nucleotides long, exclusive of a poly(A) tail. The RNA contains five principal open reading frames (ORFs), designated from the 5' terminus as encoding proteins with Mr values of 152.3K (ORF1), 26.4K (ORF2) which overlaps an 11.3K (ORF3) product, 5.8K (ORF4) which overlaps a 28.8K readthrough protein (ORF5A) which leads into the coat protein cistron of 23.7K (ORF5). The sizes and composition of the proteins encoded by the ORFs are generally similar to those found in other potexviruses; the least similar is the coat protein which nonetheless retains apparently critical consensus regions. The 5' terminus of the previously reported 0.9 kb subgenomic (sg) RNA was determined by S1 nuclease mapping and shown to begin with the sequence GAAGA, 43 nucleotides upstream from the first nucleotide of the coat protein initiation codon. The positions of the 5' end of this sgRNA and of that deduced from the nucleotide sequence for a 1.9 kb sgRNA are entirely consistent with the previously published sizes of these sgRNAs.
J Gen Virol 1991 Sep
PMID:The entire nucleotide sequence of foxtail mosaic virus RNA. 184 Jun 10

The expression of gene 1, a member of the small heat shock gene family from the Drosophila melanogaster chromosomal locus 67B was studied. In contrast to the other heat shock genes, the response of gene 1 to stress was modulated during development. In the absence of stress, gene 1 was expressed at the beginning of pupation, and at a very low level in adult males. Expression of gene 1 was substantially increased by heat shock in pupae, but was one to two orders of magnitude lower in adults or in embryos. Under the same conditions, hsp70 or hsp26 were induced to similar levels in all stages. This developmental effect could be mimicked in cultured Drosophila cells: expression of gene 1 was stimulated by heat shock in the presence, but not in the absence, of the moulting hormone ecdysterone, while the level of expression of hsp26 and hsp70 in response to heat shock was independent of the presence of the hormone. Thus, the presence and activity of the heat shock transcription factor are not sufficient for the maximal response of gene 1 to stress. These results suggest that the heat shock activator protein requires additional factors, which are developmentally regulated, to activate transcription of gene 1. Furthermore, S1 nuclease mapping analysis revealed several gene 1 mRNA species, which are generated by the use of alternative polyadenylation sites and by the use of differentially regulated transcriptional initiation sites.
Mol Gen Genet 1991 May
PMID:Response to heat shock of gene 1, a Drosophila melanogaster small heat shock gene, is developmentally regulated. 190 35

The DnaA protein is the key DNA initiation protein in Escherichia coli. Using transcriptional and translational fusions, comparative S1 nuclease mapping and immunoblot analysis, the regulation of dnaA in relation to inducible responses to DNA damage was studied. We found that DNA damage caused by mitomycin C (MC) and methyl methanesulfonate (MMS) led to a significant induction of the dnaA gene. These results strongly suggest that in response to DNA damage which inhibits DNA replication, an increased initiation capacity is induced at oriC and that, in addition to the known auto-repression, a new regulatory mechanism may be involved in the control of dnaA gene expression. Furthermore, this mechanism might be indirectly related to the SOS regulon, because lexA and recA mutants, which block the induction of the SOS response, prevent dnaA induction by MMS and MC.
Mol Gen Genet 1991 May
PMID:Expression of the dnaA gene of Escherichia coli is inducible by DNA damage. 190 39

Clinical Klebsiella pneumoniae isolates as well as Escherichia coli transformants producing the beta-lactamases SHV-2 or SHV-2a demonstrate MIC values for cefotaxime of 4 mg l-1 or 64 to greater than 128 mg l-1, respectively. The beta-lactamases differ by one possibly insignificant amino acid exchange at position number 10 of the mature protein; their kinetic parameters are rather similar. The 5' untranslated regions of both corresponding genes show no homology starting 74 nucleotides upstream to the start codon. Hybridization of intragenically annealing oligonucleotides to dot-blotted serial dilutions of total cellular RNA from E. coli transformants harbouring these genes cloned into the same vector plasmid gave a positive signal down to 1.2 micrograms (SHV-2) and 0.32 to 0.16 micrograms (SHV-2a), indicating a four to eight times higher amount of specific transcript in the case of SHV-2a. By primer extension analysis and S1 nuclease digestion the starting point to transcription was located 100 nucleotides (SHV-2) and 50 nucleotides (SHV-2a) in front of the start codon. No other transcripts of different length could be detected after prolonged exposure. Northern blot analysis demonstrated the length of the beta-lactamase mRNA to be about 1.6 kb in both cases, thus comprising a potential open reading frame downstream of the two enzymes' genes. Selective PCR amplification of both promoter regions and of the structural gene of SHV-2 and subsequent combined cloning of each of the promoters and the SHV-2 gene into pBGS19 using a BamHI restriction site introduced by three point mutations into the cloned sequences was employed to transforms E. coli DH5 alpha.(ABSTRACT TRUNCATED AT 250 WORDS)
J Gen Microbiol 1991 Jul
PMID:Different promoters of SHV-2 and SHV-2a beta-lactamase lead to diverse levels of cefotaxime resistance in their bacterial producers. 195 59

S1 nuclease protection and primer extension analyses were used to determine the 5' end of the Autographa californica nuclear polyhedrosis virus 603 open reading frame (ORF) transcript upstream of and on the opposite strand to the polyhedrin gene. These analyses suggested that the 5' end of the 603 ORF was located near the initiation site for polyhedrin gene transcription. Primer extension products of reverse transcription of 603 RNA were dependent on the presence of the TAAG sequence, an essential polyhedrin promoter element. The results could be interpreted as indicating bidirectional transcription from the TAAG element. However, the data could also be due to an artefact of antisense transcripts and RNA duplex formation in this region. Since the bidirectional transcriptional model is not consistent with other mapping data and Northern blot analysis, we conclude that the presence of antisense RNA can result in mapping artefacts and that caution must be taken in interpreting data where overlapping sense and antisense RNAs are present.
J Gen Virol 1991 Mar
PMID:The influence of antisense RNA on transcriptional mapping of the 5' terminus of a baculovirus RNA. 200 31


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