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)

The entire glycerol utilization (gylABX) operon of Streptomyces coelicolor A3(2) was cloned and its transcriptional organization and regulation was analyzed by Northern blotting, S1 nuclease mapping and transcriptional fusions. Transcription of the operon is glycerol-inducible and glucose-repressible; glyA (presumptively encoding glycerol kinase), gylB (encoding sn-glycerol-3-phosphate dehydrogenase) and gylX (a non-essential 1.1 kb sequence) are transcribed consecutively to give a 5.4 kb mRNA. Two alternative transcription termination or gyl mRNA processing sites are located within the operon; one (a discrete site) lies between gylB and gylX and the other (a heterogeneous site) positioned 3 kb into the operon, may correspond to the gylA-gylB intercistronic region. A 0.9 kb glycerol-inducible transcription unit is located immediately upstream of gylABX. Transcriptional fusion studies employing an attP site-deleted phage vector provided complementary evidence for the organization of the operon.
Mol Gen Genet 1988 Jan
PMID:Cloning and transcription analysis of the entire glycerol utilization (gylABX) operon of Streptomyces coelicolor A3(2) and identification of a closely associated transcription unit. 244 98

The alpha-Amy2 genes of wheat are a multigene family which is expressed in the aleurone cells of germinating grain under control of the plant hormone gibberellin. A subset of the genes are also expressed in developing grain. Comparison of five genomic clones containing alpha-Amy2 genes, using DNA sequence analysis and Southern hybridisation, showed that the extent of similarity between genes differed. Two of the most heterogeneous genes compared were located to the same group 7 chromosome while the most similar genes alpha-Amy2/54 and alpha-Amy2/8 were located to different ones; hence sequence variation could not be correlated to the ancestry of the alpha-Amy2 genes during the separate existence of the constituent genomes of hexaploid wheat. Expression of the cloned genes was measured using an S1 nuclease protection assay and this identified alpha-Amy2/54 and alpha-Amy2/8 as part of the subset of alpha-Amy2 genes expressed in both the developing grain and in aleurone cells. Comparison of the 5' upstream regions of all five genes showed high similarity, with the exception of one gene, up to -280 nucleotides from the transcriptional start, while similarity between alpha-Amy2/54 and alpha-Amy2/8 extended a further 90 bp upstream of this point. It is suggested that regulatory elements responsible for tissue specificity and gibberellin regulation may be located within these regions of similarity.
Mol Gen Genet 1988 Oct
PMID:Sequence heterogeneity and differential expression of the alpha-Amy2 gene family in wheat. 246 83

In heterocysts of the filamentous cyanobacterium Anabaena 7120 a specific [2Fe-2S] ferredoxin is synthesized, serving as immediate electron donor to nitrogenase. The structural gene for this heterocyst ferredoxin, fdxH, was isolated from a recombinant lambda library, using an oligonucleotide probe derived from a unique segment of the N-terminal amino acid sequence of the purified protein. The sequence of the entire fdxH coding region was determined including 3' and 5' flanking sequences. Assuming proteolytic cleavage of the first methionine residue, the molecular weight of Anabaena 7120 heterocyst ferredoxin is 10,806. Compared with the ferredoxin from vegetative cells, 47 out of 98 amino acid residues are different, including conversions within a highly conserved region responsible for binding of the iron-sulfur cluster. Northern hybridization with a 0.64 kb EcoRI DNA fragment containing the entire fdxH gene indicated two major transcripts of 0.59 and 1.85 kb, which are expressed at a late stage of heterocyst differentiation. By S1 nuclease digestion and primer extension a possible start site of transcription was mapped, 132 bp upstream of fdxH; however, neither a typical Escherichia coli nor nif-type promoter sequence was apparent. Southern hybridization detected only one copy of the fdxH gene in the Anabaena 7120 genome. FdxH is located approximately 7 kb downstream from the nifHDK gene cluster.
Mol Gen Genet 1988 Oct
PMID:Molecular cloning and nucleotide sequence analysis of the gene coding for heterocyst ferredoxin from the cyanobacterium Anabaena sp. strain PCC 7120. 246 84

The 271 nucleotides long scRNA (small cytoplasmic RNA) from Bacillus subtilis is structurally related to the Escherichia coli 4.5 S RNA (114 nucleotides), an essential molecule supposed to be involved in protein biosynthesis, but it possesses an additional moiety completely missing in the E. coli 4.5 S RNA. Both RNAs share a conserved hairpin with the eukaryotic 7SL RNAs, which mediate protein translocation as part of the signal recognition particle (SRP). We have cloned and sequenced the entire scRNA gene region from B. subtilis and have studied transcription and processing of the scRNA in B. subtilis by nuclease S1 mapping. This analysis revealed the scRNA gene to constitute a monofunctional transcription unit, expressed from a single promoter to a rho-independent terminator, yielding a precursor which extends the mature scRNA by approximately 40 nucleotides at both ends. Processing of the scRNA apparently involves only two endonucleolytic cuts and occurs first at the 5' end.
Mol Gen Genet 1989 Feb
PMID:Transcription and processing of Bacillus subtilis small cytoplasmic RNA. 246 93

We have characterized RpII215, the gene encoding the largest subunit of RNA polymerase II in Drosophila melanogaster. DNA sequencing and nuclease S1 analyses provided the primary structure of this gene, its 7 kb RNA and 215 kDa protein products. The amino-terminal 80% of the subunit harbors regions with strong homology to the beta' subunit of Escherichia coli RNA polymerase and to the largest subunits of other eukaryotic RNA polymerases. The carboxyl-terminal 20% of the subunit is composed of multiple repeats of a seven amino acid consensus sequence, Tyr-Ser-Pro-Thr-Ser-Pro-Ser. The homology domains, as well as the unique carboxyl-terminal structure, are considered in the light of current knowledge of RNA polymerase II and the properties of its largest subunit. Additionally, germline transformation demonstrated that a 9.4 kb genomic DNA segment containing the alpha-amanitin-resistant allele, RpII215C4, includes all sequences required to produce amanitin-resistant transformants.
Mol Gen Genet 1989 Jan
PMID:Analysis of the gene encoding the largest subunit of RNA polymerase II in Drosophila. 249 96

The bipartite genome of the geminivirus tomato golden mosaic virus (TGMV) contains at least six open reading frames (ORFs) with the potential to code for proteins of greater than 100 amino acids. In order to investigate the expression of these coding regions, RNA preparations from plants infected with TGMV have been examined for the presence of viral transcripts. We have identified six polyadenylated, virus-specific RNAs which correspond in size, polarity and map location to the six ORFs. Primer extension and S1 nuclease analysis of an RNA which maps to the viral coat protein gene (ORF AR1) has shown that this transcription unit begins at nucleotide 319 or 320 and ends in the vicinity of nucleotide 1090 of the TGMV A sequence, in agreement with a previous report (I.T.D. Petty, R.H.A. Coutts, and K.W. Buck, 1988, J. Gen. Virol. 69, 1359-1365). The data presented here confirm the bidirectional transcription strategy implied by the arrangement of ORFs on both strands of double-stranded TGMV DNA intermediates and lay the ground-work for further studies of viral transcription and its control.
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PMID:Identification of tomato golden mosaic virus-specific RNAs in infected plants. 254 38

The temperate, transposable bacteriophages D108 and Mu are highly homologous, but differ in their lef-end regulatory regions. We have previously cloned the gene encoding the D108 thermo-sensitive (cts) repressor under the control of the lactUV5 promoter. In this work, we report that crude protein extracts containing highly-expressed D108 repressor protect a 77 bp region of DNA, located between 863 bp and 940 bp from the D108 lef--end, from both exonuclease III and DNase I hydrolysis. Nucleotide sequence analysis of this region reveals that is also contains DNA sequences homologous to the consensus DNA-binding site of the Escherichia coli protein, Integration Host Factor (IHF). Crude protein extracts containing highly-expressed IHF specifically bind to, and retard the migration of, DNA fragments containing the D108 regulatory region, and the DNA sequence which IHF protects from DNase I cleave lies directly within the D108 repressor binding region. There are two apparent repressor-specific S1 nuclease-resistant RNA suggests that transcription from the early region promoter, Pe may initiate at or about 1000 bp from the left-end of the D108 genome. Thus though, D108 and Mu utilize three analogous proteins (repressor, ner, and IHF) and the same apparent promoters for early gene regulation and the lytic/lysogenic decision, the organization of these regulatory components is apparently different, suggesting different mechanisms of control of gene expression.
Mol Gen Genet 1989 Jun
PMID:Regulation of repressor and early gene expression in Mu-like transposable bacteriophage D108. 254 79

Hepatitis A virus (HAV) particles harbouring a physically defective RNA genome have been reported to occur in all HAV-infected cell culture systems analysed so far. The most prominent defects consist of three distinct overlapping deletions in the region of the HAV genome encoding the structural proteins. By probing for the endpoints of these deletions in RNA samples using S1 nuclease and exonuclease VII mapping, we obtained suggestive evidence for the existence also of defective genomes in HAV particles present in faecal specimens, in viraemic blood collected in the course of hepatitis A virus infection in man, as well as in the liver of an experimentally infected marmoset monkey. The deletions identified extend from nucleotide (nt) 1200 to nt 3820 and from nt 1200 to nt 3240 of the HAV genome. They are compatible with two of the deletions detected in particles grown in vitro in cell cultures and shown to interfere with the replication of standard hepatitis A virions.
J Gen Virol 1989 Dec
PMID:Detection of defective genomes in hepatitis A virus particles present in clinical specimens. 255 63

The methicillin resistance determinant (mec) in Staphylococcus aureus resides on additional DNA not present in isogenic sensitive cells. However, besides mec, other chromosomally determined factors are essential for expression of methicillin resistance. We cloned and characterized a chromosomally determined gene which encodes a factor essential for the expression of methicillin resistance (femA) in S. aureus. femA mapped in chromosomal segment number 18, genetically very distant from the methicillin resistance determinant (mec). The product of femA was a protein of an apparent size of 48 kDa. FemA restored methicillin resistance in S. aureus that had become sensitive to methicillin by insertion of omega 2003 (femA::Tn551). Although FemA was needed for cell growth in the presence of beta-lactam antibiotics, it had no influence on the synthesis of the low affinity, additional penicillin-binding protein (PBP2') encoded by mec and known to be essential for cell wall synthesis in the presence of inhibitory concentrations of methicillin. Nucleotide sequence analysis, Northern RNA blotting and S1 nuclease RNA mapping suggested that femA was transcribed on a polycistronic mRNA. This mRNA contained the coding region (ORF419) producing a protein of 47 kDa. The nucleotide and amino acid sequence of FemA showed homologies with ORF419, suggesting that these genes arose by gene duplication. In addition we present evidence for a second chromosomal factor, femB, involved in expression of methicillin resistance which maps close to femA.
Mol Gen Genet 1989 Oct
PMID:FemA, a host-mediated factor essential for methicillin resistance in Staphylococcus aureus: molecular cloning and characterization. 255 14

Transcription of the structural genes for nitrogenase (nifHDK) in Azospirillum brasilense Sp7 was analysed using Northern blots of total RNA extracted from cultures grown under nitrogen-fixing conditions. Hybridization with an internal nifH probe revealed two transcripts, a major one (by concentration) of 1.1 kb corresponding to nifH and a minor one of 5.6 kb corresponding to nifHDK. Hybridization with nifD or nifK probes revealed the minor transcript of 5.6 kb. This confirms that the nifHDK genes are organized as a single transcription unit and suggests regulation at the level of termination of transcription. The complete nucleotide sequence of nifH was established and the DNA region upstream of the initiation codon was analysed for transcription and translation signals. The nifH open reading frame (ORF) is preceded by an NtrA-dependent promoter and two elements homologous to upstream activator sequences (UAS) required for NifA-mediated activation in other diazotrophs. Promoter mapping with S1 nuclease revealed two start sites located 10 bp and 40 bp downstream of the NtrA-dependent promoter.
Mol Gen Genet 1989 Dec
PMID:Regulation of transcription and promoter mapping of the structural genes for nitrogenase (nifHDK) of Azospirillum brasilense Sp7. 260 30


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