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
Vsr endonuclease plays a crucial role in the repair of TG mismatched base pairs, which are generated by the spontaneous degradation of methylated cytidines; Vsr recognizes the mismatched base pair and cleaves the phosphate backbone 5' to the thymidine. We have determined the crystal structure of a truncated form of this endonuclease at 1.8 A resolution. The protein contains one structural zinc-binding module. Unexpectedly, its overall topology resembles members of the type II restriction endonuclease family. Subsequent mutational and biochemical analyses showed that certain elements in the catalytic site are also conserved. However, the identification of a critical histidine and evidence of an active site metal-binding coordination that is novel to endonucleases indicate a distinct catalytic mechanism.
Crystallographic and functional studies of very short patch repair endonuclease.,Tsutakawa SE, Muto T, Kawate T, Jingami H, Kunishima N, Ariyoshi M, Kohda D, Nakagawa M, Morikawa K Mol Cell. 1999 May;3(5):621-8. PMID:10360178[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Tsutakawa SE, Muto T, Kawate T, Jingami H, Kunishima N, Ariyoshi M, Kohda D, Nakagawa M, Morikawa K. Crystallographic and functional studies of very short patch repair endonuclease. Mol Cell. 1999 May;3(5):621-8. PMID:10360178
