3G6V

DNA synthesis across an abasic lesion by human DNA polymerase-iota

Summary for 3G6V

• Entry DOI: 10.2210/pdb3g6v/pdb
• Related: 2fll 3G6X 3G6Y
• Descriptor: DNA polymerase iota, Primer DNA strand, Template DNA strand, ... (6 entities in total)
• Functional Keywords: dna polymerase, y-family, lesion bypass, abasic site, ternary complex, dna damage, dna repair, dna replication, dna synthesis, dna-binding, dna-directed dna polymerase, magnesium, metal-binding, mutator protein, nucleotidyltransferase, nucleus, schiff base, transferase, replication-dna complex, replication/dna
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 3
• Total formula weight: 53194.83

Authors

Nair, D.T.,Aggarwal, A.K. (deposition date: 2009-02-09, release date: 2009-05-12, Last modification date: 2023-09-06)

Primary citation

Nair, D.T.,Johnson, R.E.,Prakash, L.,Prakash, S.,Aggarwal, A.K.
DNA Synthesis across an Abasic Lesion by Human DNA Polymerase iota
Structure, 17:530-537, 2009

PubMed Abstract: Abasic sites are among the most abundant DNA lesions formed in human cells, and they present a strong block to replication. DNA polymerase iota (Poliota) is one of the few DNA Pols that does not follow the A-rule opposite an abasic site. We present here three structures of human Poliota in complex with DNAs containing an abasic lesion and dGTP, dTTP, or dATP as the incoming nucleotide. The structures reveal a mechanism of translesion synthesis across an abasic lesion that differs from that in other Pols. Both the abasic lesion and the incoming dNTPs are intrahelical and are closely apposed across a constricted active site cleft. The dNTPs partake in distinct networks of hydrogen bonds in the "void" opposite the lesion. These different patterns of hydrogen bonds, as well as stacking interactions, may underlie Poliota's small preference for insertion of dGTP over other nucleotides opposite this common lesion.

PubMed: 19368886
DOI: 10.1016/j.str.2009.02.015

Experimental method

X-RAY DIFFRACTION (2.2 Å)