TY - JOUR
T1 - Structure of human DNA polymerase κ inserting dATP opposite an 8-OxoG DNA lesion
AU - Vasquez-Del Carpio, Rodrigo
AU - Silverstein, Timothy D.
AU - Lone, Samer
AU - Swan, Michael K.
AU - Choudhury, Jayati R.
AU - Johnson, Robert E.
AU - Prakash, Satya
AU - Prakash, Louise
AU - Aggarwal, Aneel K.
PY - 2009/6/2
Y1 - 2009/6/2
N2 - Background: Oxygen-free radicals formed during normal aerobic cellular metabolism attack bases in DNA and 7,8-dihydro-8-oxoguanine (8-oxoG) is one of the major lesions formed. It is amongst the most mutagenic lesions in cells because of its dual coding potential, wherein 8-oxoG(syn) can pair with an A in addition to normal base pairing of 8-oxoG(anti) with a C. Human DNA polymerase κ (Polk) is a member of the newly discovered Y-family of DNA polymerases that possess the ability to replicate through DNA lesions. To understand the basis of Polk's preference for insertion of an A opposite 8-oxoG lesion, we have solved the structure of Polk in ternary complex with a template-primer presenting 8-oxoG in the active site and with dATP as the incoming nucleotide. Methodology and Principal Findings: We show that the Polk active site is well-adapted to accommodate 8-oxoG in the syn conformation. That is, the polymerase and the bound template-primer are almost identical in their conformations to that in the ternary complex with undamaged DNA. There is no steric hindrance to accommodating 8-oxoG in the syn conformation for Hoogsteen base-paring with incoming dATP. Conclusions and Significance: The structure we present here is the first for a eukaryotic translesion synthesis (TLS) DNA polymerase with an 8-oxoG:A base pair in the active site. The structure shows why Polk is more efficient at inserting an A opposite the 8-oxoG lesion than a C. The structure also provides a basis for why Polk is more efficient at inserting an A opposite the lesion than other Y-family DNA polymerases.
AB - Background: Oxygen-free radicals formed during normal aerobic cellular metabolism attack bases in DNA and 7,8-dihydro-8-oxoguanine (8-oxoG) is one of the major lesions formed. It is amongst the most mutagenic lesions in cells because of its dual coding potential, wherein 8-oxoG(syn) can pair with an A in addition to normal base pairing of 8-oxoG(anti) with a C. Human DNA polymerase κ (Polk) is a member of the newly discovered Y-family of DNA polymerases that possess the ability to replicate through DNA lesions. To understand the basis of Polk's preference for insertion of an A opposite 8-oxoG lesion, we have solved the structure of Polk in ternary complex with a template-primer presenting 8-oxoG in the active site and with dATP as the incoming nucleotide. Methodology and Principal Findings: We show that the Polk active site is well-adapted to accommodate 8-oxoG in the syn conformation. That is, the polymerase and the bound template-primer are almost identical in their conformations to that in the ternary complex with undamaged DNA. There is no steric hindrance to accommodating 8-oxoG in the syn conformation for Hoogsteen base-paring with incoming dATP. Conclusions and Significance: The structure we present here is the first for a eukaryotic translesion synthesis (TLS) DNA polymerase with an 8-oxoG:A base pair in the active site. The structure shows why Polk is more efficient at inserting an A opposite the 8-oxoG lesion than a C. The structure also provides a basis for why Polk is more efficient at inserting an A opposite the lesion than other Y-family DNA polymerases.
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U2 - 10.1371/journal.pone.0005766
DO - 10.1371/journal.pone.0005766
M3 - Article
C2 - 19492058
AN - SCOPUS:66849126006
SN - 1932-6203
VL - 4
JO - PloS one
JF - PloS one
IS - 6
M1 - e5766
ER -