2FLL

Ternary complex of human DNA polymerase iota with DNA and dTTP

Summary for 2FLL

• Entry DOI: 10.2210/pdb2fll/pdb
• Related: 1T3N 2AZL 2FLN 2FLP
• Descriptor: DNA primer strand, DNA template strand, DNA polymerase iota, ... (6 entities in total)
• Functional Keywords: dna polymerase, lesion bypass, y-family, ternary complex, p6522, replication-dna complex, replication/dna
• Biological source: Homo sapiens (human)
• Cellular location: Nucleus: Q9UNA4
• Total number of polymer chains: 3
• Total formula weight: 52989.72

Authors

Nair, D.T.,Johnson, R.E.,Prakash, L.,Prakash, S.,Aggarwal, A.K. (deposition date: 2006-01-06, release date: 2006-12-12, Last modification date: 2023-08-30)

Primary citation

Nair, D.T.,Johnson, R.E.,Prakash, L.,Prakash, S.,Aggarwal, A.K.
An incoming nucleotide imposes an anti to syn conformational change on the templating purine in the human DNA polymerase-iota active site.
Structure, 14:749-755, 2006

PubMed Abstract: Substrate-induced conformational change of the protein is the linchpin of enzymatic reactions. Replicative DNA polymerases, for example, convert from an open to a closed conformation in response to dNTP binding. Human DNA polymerase-iota (hPoliota), a member of the Y family of DNA polymerases, differs strikingly from other polymerases in its much higher proficiency and fidelity for nucleotide incorporation opposite template purines than opposite template pyrimidines. We present here a crystallographic analysis of hPoliota binary complexes, which together with the ternary complexes show that, contrary to replicative DNA polymerases, the DNA, and not the polymerase, undergoes the primary substrate-induced conformational change. The incoming dNTP "pushes" templates A and G from the anti to the syn conformation dictated by a rigid hPoliota active site. Together, the structures posit a mechanism for template selection wherein dNTP binding induces a conformational switch in template purines for productive Hoogsteen base pairing.

PubMed: 16615915
DOI: 10.1016/j.str.2006.01.010

Experimental method

X-RAY DIFFRACTION (2.6 Å)