Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.30.2 (endonuclease)
 18,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In Escherichia coli K-12, the Dcm methyltransferase catalyses methylation of the inner cytosine residue in the sequence CCA/TGG. Hydrolytic deamination of 5-methylcytosine bases in DNA leads to thymine residues, and hence to T/G mismatches, pre-mutagenic DNA lesions consisting of two natural DNA constituents and thus devoid of an obvious marker of the damaged DNA strand. These mismatches are corrected by the VSP repair pathway, which is characterized by very short patches of DNA repair synthesis. It depends on genes vsr and polA and is strongly stimulated by mutL and mutS. The vsr gene product (Vsr; Mr 18,000) was purified and characterized as a DNA mismatch endonuclease, a unique and hitherto unknown type of enzyme. Vsr endonuclease nicks double-stranded DNA within the sequence CTA/TGN or NTA/TGG next to the underlined thymidine residue, which is mismatched to 2'-deoxyguanosine. The incision is mismatch-dependent and strand-specific. These results illustrate how Vsr endonuclease initiates VSP mismatch repair.
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PMID:The vsr gene product of E. coli K-12 is a strand- and sequence-specific DNA mismatch endonuclease. 194 37

The substrate spectrum of Vsr DNA mismatch endonuclease of Escherichia coli K-12 was investigated using fluorescence-labelled oligonucleotide substrates and a DNA sequencer for detection and quantification of substrates and reaction products. Fourteen substrates were found to be processed by the enzyme, which differ in one or two positions from the canonical pentanucleotide sequence CTA/TGG (T mismatched to G). Relative second-order rate constants of these substrates were determined in groups of four by multiple substrate kinetics and compared to the underresentation of the corresponding pentanucleotides in the E. coli K-12 genome. The high quality of correlation further establishes active mutagenesis by VSP repair as a significant driving force of the evolution of the E. coli K-12 genome and provides clues to its possible selective value.
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PMID:Substrate preferences of Vsr DNA mismatch endonuclease and their consequences for the evolution of the Escherichia coli K-12 genome. 782 16

To evaluate the association between complement factor H (CFH) gene polymorphism and the risk of exudative age-related macular degeneration (AMD) in a case-control study in a Chinese cohort. One hundred and thirty-six exudative AMD patients and 140 age- and sex-matched control subjects were recruited. We genotyped 3 common single nucleotide polymorphisms (SNPs), namely, -257C>T (rs3753394), Y402H (rs1061170) and IVS15 (rs1329428), genetic analyses were performed on all available genotype data. All the possible haplotypes of these 3 SNPs were detected. Polymerase chain reaction (PCR) and allele-specific restriction endonuclease digestion were performed, some PCR products of these 3 SNPs were sequenced. The risk alleles (T, C or G) of the 3 SNPs conferred 1.72-fold, 3.14-fold, and 1.79-fold of increased likelihood of the disease, respectively (P<0.05). The heterozygous genotype in rs1061170 (TC) revealed significant association, meanwhile rs3753394 and rs1329428 had a slight association with the disease, respectively. Significant differences were shown in the risk alleles in the 3 SNPs among different Chinese cohort. Low linkage disequilibrium was found among the 3 SNPs. The haplotypes TCG and CTG revealed as risk factors, whereas the protective haplotype CTA was over-represented in controls. We found significant association between risk alleles (T, C or G) of the 3 SNPs and the disease. The genetic divergence across multiple populations within Chinese existed. Risk haplotypes and protective haplotype were found in this study.
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PMID:Correlation of complement factor H gene polymorphisms with exudative age-related macular degeneration in a Chinese cohort. 2111 Oct 31