3H4B

Ternary complex of human DNA polymerase iota with template U/T and incoming dATP

Summary for 3H4B

• Entry DOI: 10.2210/pdb3h4b/pdb
• Related: 3H40 3H4O
• Descriptor: DNA polymerase iota, 5'-D(*AP*GP*GP*AP*CP*CP*(DOC))-3', 5'-D(*TP*(BRU)P*GP*GP*GP*TP*CP*CP*T)-3', ... (6 entities in total)
• Functional Keywords: dna polymerase iota, replication, 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)
• Cellular location: Nucleus: Q9UNA4
• Total number of polymer chains: 3
• Total formula weight: 49446.61

Authors

Jain, R.,Nair, D.T.,Johnson, R.E.,Prakash, L.,Prakash, S.,Aggarwal, A.K. (deposition date: 2009-04-18, release date: 2009-07-21, Last modification date: 2023-09-06)

Primary citation

Jain, R.,Nair, D.T.,Johnson, R.E.,Prakash, L.,Prakash, S.,Aggarwal, A.K.
Replication across template T/U by human DNA polymerase-iota.
Structure, 17:974-980, 2009

PubMed Abstract: Human DNA polymerase-iota (Poliota) incorporates correct nucleotides opposite template purines with a much higher efficiency and fidelity than opposite template pyrimidines. In fact, the fidelity opposite template T is so poor that Poliota inserts an incorrect dGTP approximately 10 times better than it inserts the correct dATP. We determine here how a template T/U is accommodated in the Poliota active site and why a G is incorporated more efficiently than an A. We show that in the absence of incoming dATP or dGTP (binary complex), template T/U exists in both syn and anti conformations, but in the presence of dATP or dGTP (ternary complexes), template T/U is predominantly in the anti conformation. We also show that dATP and dGTP insert differently opposite template T/U, and that the basis of selection of dGTP over dATP is a hydrogen bond between the N2 amino group of dGTP and Gln59 of Poliota.

PubMed: 19604477
DOI: 10.1016/j.str.2009.04.011

Experimental method

X-RAY DIFFRACTION (2.85 Å)