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)

A nuclease that could be recovered from the supernatant of cultures, as well as from cell-free extracts, of the cyanobacterium Anabaena sp. PCC 7120 was identified as a 29 kDa polypeptide by its ability to degrade DNA after electrophoresis in DNA-containing SDS-polyacrylamide gels. Some clones of a gene library of strain PCC 7120 established in Escherichia coli were found to produce the 29 kDa nuclease. The nucA gene encoding this nuclease was subcloned and sequenced. The deduced polypeptide, NucA, had a molecular weight of 29,650, presented a presumptive signal peptide in its N-terminal region and showed homology to the products of the nuc gene from Serratia marcescens and the NUC1 gene from Saccharomyces cerevisiae. The NucA protein from Anabaena itself, or from the cloned nucA gene expressed in E. coli, catalysed the degradation of both RNA and DNA, had the potential to act as an endonuclease, and functioned best in the presence of Mn2+ or Mg2+. An Anabaena nucA insertional mutant was generated which failed to produce the 29 kDa nuclease.
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PMID:Identification, genetic analysis and characterization of a sugar-non-specific nuclease from the cyanobacterium Anabaena sp. PCC 7120. 134 21

Endo.SceI most likely initiates homologous recombination of yeast mitochondrial genome through sequence-specific double-strand scission of DNA. According to the double-strand break-repair model for the mechanism of homologous recombination, DNA ends created by sequence-specific endonucleases have to be processed by exonucleases. The major mitochondrial exonuclease (encoded by NUC1) has been shown to greatly affect the length of conversion tracts at the 21S rRNA locus when site-specific gene conversion is induced by omega endonuclease. In order to examine the role of the NUC1 nuclease in the Endo.SceI-induced recombination, recombination frequencies were measured after crossing of parental strains either in the presence or absence of NUC1 nuclease activity. The frequency of gene conversion in the oli2 locus induced by Endo.SceI was not reduced by disruption of the NUC1 gene. This result strongly implicates the presence of multiple exonucleases for the processing of the DNA ends created by sequence-specific endonucleases.
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PMID:A sequence-specific endonuclease, Endo.SceI, can efficiently induce gene conversion in yeast mitochondria lacking a major exonuclease. 839 97

We isolated the cDNA of the fission yeast mitochondrial endonuclease SpNUC1, which consists of 322 amino acids and has a significant homology with the budding yeast NUC1 and mammalian endonuclease G. Comparison of the cDNA sequence with the genomic sequence showed that the gene consists of three exons and two introns and spans 1.31 kb. The enzyme localization in mitochondria was demonstrated by expressing the SpNUC1-green fluorescent protein fusion in the yeast. The endonuclease was activated by truncation of the amino-terminal region of the protein, indicating that the enzyme is encoded as an inactive precursor. The active enzyme degraded single-stranded DNA and RNA, the activity being dependent on Mg(2+) (Mn(2+)).
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PMID:Isolation and characterization of the Schizosaccharomyces pombe cDNA encoding the mitochondrial endonuclease(1). 1140 79

Mammalian DNase II enzymes and the Caenorhabditis elegans homolog NUC-1 have recently been shown to be critically important during engulfment-mediated clearance of DNA. In this report, we describe the cloning and characterization of the gene encoding Drosophila DNase II. Database queries using the C. elegans NUC-1 protein sequence identified a highly homologous open reading frame in Drosophila (CG7780) that could encode a similar enzyme. Analysis of crude protein extracts revealed that wild-type Drosophila contain a potent acid endonuclease activity with cleavage preferences similar to DNase II/NUC1, while the same activity was markedly reduced in an acid DNase hypomorphic mutant line. Furthermore, the pattern of cleavage products generated from an end-labeled substrate by hypomorphic-line extracts was significantly altered in comparison to the pattern generated by wild-type extracts. Sequence analysis of CG7780 DNA and mRNA revealed that the hypomorphic line contains a missense mutation within the coding region of this gene. Additionally, Northern analysis demonstrated that CG7780 expression is normal in the mutant line, which in combination with the lowered/altered enzymatic activity and sequencing data suggested a defect in the CG7780 protein. To conclusively determine if CG7780 encoded the Drosophila equivalent of DNase II/NUC-1, transgenic lines expressing wild-type CG7780 in the mutant background were generated and subsequently shown to complement the mutant phenotype. Our results, therefore, provide compelling evidence that the predicted gene CG7780 encodes Drosophila DNase II (dDNase II), an enzyme related in sequence and activity to mammalian DNase II. Interestingly, overexpression of CG7780 both ubiquitously and in specific tissues failed to elicit any discernable phenotype.
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PMID:Drosophila acid DNase is a homolog of mammalian DNase II. 1224 12