3osp
Structure of rev1Structure of rev1
Structural highlights
FunctionREV1_YEAST Deoxycytidyl transferase involved in DNA repair. Transfers a dCMP residue from dCTP to the 3'-end of a DNA primer in a template-dependent reaction. May assist in the first step in the bypass of abasic lesions by the insertion of a nucleotide opposite the lesion. Required for normal induction of mutations by physical and chemical agents. Involved in mitochondrial DNA mutagenesis.[1] [2] [3] Publication Abstract from PubMedAbasic (apurinic/apyrimidinic) sites are among the most abundant DNA lesions in humans, and they present a strong block to replication. They are also highly mutagenic because when replicative DNA polymerases manage to insert a nucleotide opposite the lesion, they prefer to insert an A. Rev1, a member of Y-family DNA polymerases, does not obey the A-rule. This enzyme inserts a C opposite an abasic lesion with much greater catalytic efficiency than an A, G, or T. We present here the structure of yeast Rev1 in ternary complex with DNA containing an abasic lesion and with dCTP as the incoming nucleotide. The structure reveals a mechanism of synthesis across an abasic lesion that differs from that in other polymerases. The lesion is driven to an extrahelical position, and the incorporation of a C is mediated by an arginine (Arg324) that is conserved in all known orthologs of Rev1, including humans. The hydrophobic cavity that normally accommodates the unmodified G is instead filled with water molecules. Since Gs are especially prone to depurination through a spontaneous hydrolysis of the glycosidic bond, the ability of Rev1 to stabilize an abasic lesion in its active site and employ a surrogate arginine to incorporate a C provides a unique means for the "error-free" bypass of this noninstructional lesion. DNA synthesis across an abasic lesion by yeast REV1 DNA polymerase.,Nair DT, Johnson RE, Prakash L, Prakash S, Aggarwal AK J Mol Biol. 2011 Feb 11;406(1):18-28. Epub 2010 Dec 15. PMID:21167175[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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