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
The crystal structure of very short patch repair (Vsr) endonuclease, in complex with Mg2+ and with duplex DNA containing a TG mismatch, has been determined at 2.3 A resolution. In E. coli, the enzyme recognizes a TG mismatched base pair, generated after spontaneous deamination of methylated cytosines, and cleaves the phosphate backbone on the 5' side of the thymine. Extensive interactions between the DNA and the protein characterize a novel recognition mechanism, where three aromatic residues intercalate from the major groove into the DNA to strikingly deform the base pair stacking. With the presence of a cleaved DNA intermediate in the active center, the structure of the Vsr/DNA complex provides detailed insights into the catalytic mechanism for endonuclease activity.
Recognition of a TG mismatch: the crystal structure of very short patch repair endonuclease in complex with a DNA duplex.,Tsutakawa SE, Jingami H, Morikawa K Cell. 1999 Dec 10;99(6):615-23. PMID:10612397[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Tsutakawa SE, Jingami H, Morikawa K. Recognition of a TG mismatch: the crystal structure of very short patch repair endonuclease in complex with a DNA duplex. Cell. 1999 Dec 10;99(6):615-23. PMID:10612397
