کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1980205 1061829 2013 13 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Evidence that YycJ is a novel 5′–3′ double-stranded DNA exonuclease acting in Bacillus anthracis mismatch repair
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی زیست شیمی
پیش نمایش صفحه اول مقاله
Evidence that YycJ is a novel 5′–3′ double-stranded DNA exonuclease acting in Bacillus anthracis mismatch repair
چکیده انگلیسی

The most important system for correcting replication errors that survive the built in editing system of DNA polymerase is the mismatch repair (MMR) system. We have identified a novel mutator strain yycJ in Bacillus anthracis. Mutations in the yycJ gene result in a spontaneous mutator phenotype with a mutational frequency and specificity comparable to that of MMR-deficient strains such as those with mutations in mutL or mutS. YycJ was annotated as a metallo-β-lactamase (MβL) super family member with unknown activity. In this study we carried out a biochemical characterization of YycJ and demonstrated that a recombinant YycJ protein possesses a 5′–3′ exonuclease activity at the 5′ termini and at nicks of double-stranded DNA. This activity requires a divalent metal cofactor Mn2+ and is stimulated by 5′-phosphate ends of duplex DNA. The mutagenesis of conserved amino acid residues revealed that in addition to the five MβL family conserved motifs, YycJ appears to have its specific motifs that can be used to distinguish YycJ from other closely related MβL family members. A phylogenetic survey showed that putative YycJ homologs are present in several bacterial phyla as well as in members of the Methanomicrobiales and Thermoplasmales from Archaea. We propose that YycJ represents a new group of MβL fold exonucleases, which is likely to act in the recognition of MMR entry point and subsequent removal of the mismatched base in certain MutH-less bacterial species.


► The 6xHis-tagged B. anthracis YycJ protein is purified from B. anthracis.
► B. anthracis YycJ possesses a 5′–3′ exonuclease activity at the 5′ termini and at nicks of double-stranded DNA.
► This activity requires a divalent metal cofactor Mn2+ and is stimulated by 5′-phosphate ends of duplex DNA.
► YycJ homologs and conserved amino acid residues are analyzed.
► B. subtilis yycJ mutants are spontaneous mutators.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: DNA Repair - Volume 12, Issue 5, 1 May 2013, Pages 334–346
نویسندگان
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