Structural highlights
Function
[VSR_ECOLI] Deamination of 5-methylcytosine in DNA results in T/G mismatches. If unrepaired, these mismatches can lead to C-to-C transition mutations. The very short patch (VSP) repair process in E.coli counteracts the mutagenic process by repairing the mismatches in favor of the G-containing strand. This enzyme is an endonuclease that nicks double-stranded DNA within the sequence CT(AT)GN or NT(AT)GG next to the thymidine residue that is mismatched to 2'-deoxyguanosine. The incision is mismatch-dependent and strand-specific.
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Very-short-patch repair (Vsr) enzymes occur in a variety of bacteria, where they initiate nucleotide excision repair of G:T mismatches arising by deamination of 5-methyl-cytosines in specific regulatory sequences. We have now determined the structure of the archetypal dcm-Vsr endonuclease from Escherichia coli bound to the cleaved authentic hemi-deaminated/hemi-methylated dcm sequence 5'-C-OH-3' 5'-p-T-p-A-p-G-p-G-3'/3'-G-p-G-p-T-p(Me5)C-p-C formed by self-assembly of a 12mer oligonucleotide into a continuous nicked DNA superhelix. The structure reveals the presence of a Hoogsteen base pair within the deaminated recognition sequence and the substantial distortions of the DNA that accompany Vsr binding to product sites.
Crystal structure of the Escherichia coli dcm very-short-patch DNA repair endonuclease bound to its reaction product-site in a DNA superhelix.,Bunting KA, Roe SM, Headley A, Brown T, Savva R, Pearl LH Nucleic Acids Res. 2003 Mar 15;31(6):1633-9. PMID:12626704[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Bunting KA, Roe SM, Headley A, Brown T, Savva R, Pearl LH. Crystal structure of the Escherichia coli dcm very-short-patch DNA repair endonuclease bound to its reaction product-site in a DNA superhelix. Nucleic Acids Res. 2003 Mar 15;31(6):1633-9. PMID:12626704
