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 amino acid sequence of nuclease S1, a nuclease which cleaves both single-stranded DNA and RNA, from Aspergillus oryzae was determined. Reduced and S-carboxymethylated or S-aminoethylated nuclease S1 was digested with Achromobacter protease I, Staphylococcus aureus V8 protease, or endoproteinase Asp-N. Peptides thus obtained were purified by reverse-phase high-performance liquid chromatography and sequenced, and the complete primary structure was established. Nuclease S1 consists of a single peptide chain of 267 amino acid residues bearing N-glycosylated Asns 92 and 228. Five half-cystine residues are present at positions 25, 72, 80, 85, and 216, and the latter four residues are implicated in the formation of disulfide bonds by analogy with those in nuclease P1. Two short stretches of sequences involving His 60 and His 125 are shown to be identical with those involving active site His 119 in bovine ribonuclease A and active-site His 134 in porcine deoxyribonuclease I, respectively.
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PMID:Amino acid sequence of nuclease S1 from Aspergillus oryzae. 193 22

DNA damage induced by carboplatin [cis-diammine-(1, 1-cyclobutanedicarboxylato)platinum(II)] was studied in vitro in comparison with cisplatin [cis-diammine-dichloroplatinum(II)]. The drug-induced DNA damage monitored by conformational change of pUC18 plasmid DNA showed that carboplatin required 10 times higher drug concentration and 7.5 times longer incubation time than those of cisplatin to induce the same degree of conformational change on plasmid DNA. The carboplatin-induced DNA damage was promoted by the increase of pH of the reaction mixture for platinum-DNA adduct formation. Sequence gel analysis of carboplatin-damaged DNA indicated that carboplatin attacked preferentially the sequence of GG >> AG > GA > GNG in the order, similarly to the case of cisplatin. DNA adducts formed by carboplatin were analyzed by HPLC after a sequential digestion of carboplatin-treated DNA with deoxyribonuclease I and S1 nuclease. A single peak having the same retention time as that of bifunctional adduct of (dGMP)2Pt(NH3)2 appeared by treating DNA with carboplatin. The adduct was assigned to be d(pGpG) > Pt(NH3)2. These results suggested that carboplatin induces the same platinum-DNA adducts as those induced by cisplatin, and that the difference in efficiency or kinetics of DNA damage between carboplatin and cisplatin is due to difference of aquation rate between them.
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PMID:A comparison of in vitro platinum-DNA adduct formation between carboplatin and cisplatin. 808 11

The Na, K-ATPase is formed by two major subunits (alpha and beta) encoded by a gene family of at least four alpha and three beta isoforms. These genes show distinctive expression patterns involving complex tissue-specific and developmental regulation, although the control mechanisms are not well understood. Here we study the role of chromatin structure in the tissue-specific expression of rat Na, K-ATPase beta2 isoform, which is mainly found in the central nervous system. We have examined the presence and characteristics of nuclease hypersensitive sites and the cytosine methylation patterns in the 5'-flanking region of the beta2 isoform gene from various nuclear preparations. Our results show that in this 5'-flanking region there is only one nuclease hypersensitive site. It is located upstream of the transcription initiation site and shows tissue-specific characteristics. Digestion with deoxyribonuclease I (DNase I), S1 nuclease and micrococcal nuclease yield patterns consistent with a triple-helix structure present only in the active state of the promoter. We also demonstrate that the 5'-flanking region of the beta2 gene co-localizes with a CpG island free of methylation in every tissue tested. The results presented here support a role for specific chromatin remodeling events in the regulation of the Na, K-ATPase beta2 gene expression. They also provide the basis for future studies of the transcription factors involved in the regulation of this gene.
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PMID:Chromatin structure analysis of the rat Na, K-ATPase beta2 gene 5'-flanking region. 1194 94