6AS7

CRYSTAL STRUCTURE OF THE CATALYTIC CORE OF HUMAN DNA POLYMERASE ALPHA IN TERNARY COMPLEX WITH AN DNA-PRIMED DNA TEMPLATE AND DCTP

6AS7 の概要

• エントリーDOI: 10.2210/pdb6as7/pdb
• 関連するPDBエントリー: 4qcl
• 分子名称: DNA polymerase alpha catalytic subunit, DNA (5'-D(*GP*CP*CP*TP*GP*GP*AP*GP*CP*GP*C)-3'), DNA (5'-D(*AP*GP*GP*CP*GP*CP*TP*CP*CP*AP*GP*GP*C)-3'), ... (7 entities in total)
• 機能のキーワード: b-family dna polymerase, dna replication, replication, replication-dna complex, replication/dna
• 由来する生物種: Homo sapiens (Human); 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 113570.22

構造登録者

Tahirov, T.H.,Baranovskiy, A.G.,Babayeva, N.D. (登録日: 2017-08-23, 公開日: 2018-03-14, 最終更新日: 2023-10-04)

主引用文献

Baranovskiy, A.G.,Duong, V.N.,Babayeva, N.D.,Zhang, Y.,Pavlov, Y.I.,Anderson, K.S.,Tahirov, T.H.
Activity and fidelity of human DNA polymerase alpha depend on primer structure.
J. Biol. Chem., 293:6824-6843, 2018

PubMed Abstract: DNA polymerase α (Polα) plays an important role in genome replication. In a complex with primase, Polα synthesizes chimeric RNA-DNA primers necessary for replication of both chromosomal DNA strands. During RNA primer extension with deoxyribonucleotides, Polα needs to use double-stranded helical substrates having different structures. Here, we provide a detailed structure-function analysis of human Polα's interaction with dNTPs and DNA templates primed with RNA, chimeric RNA-DNA, or DNA. We report the crystal structures of two ternary complexes of the Polα catalytic domain containing dCTP, a DNA template, and either a DNA or an RNA primer. Unexpectedly, in the ternary complex with a DNA:DNA duplex and dCTP, the "fingers" subdomain of Polα is in the open conformation. Polα induces conformational changes in the DNA and hybrid duplexes to produce the universal double helix form. Pre-steady-state kinetic studies indicated for both duplex types that chemical catalysis rather than product release is the rate-limiting step. Moreover, human Polα extended DNA primers with higher efficiency but lower processivity than it did with RNA and chimeric primers. Polα has a substantial propensity to make errors during DNA synthesis, and we observed that its fidelity depends on the type of sugar at the primer 3'-end. A detailed structural comparison of Polα with other replicative DNA polymerases disclosed common features and some differences, which may reflect the specialization of each polymerase in genome replication.

PubMed: 29555682
DOI: 10.1074/jbc.RA117.001074

実験手法

X-RAY DIFFRACTION (2.95 Å)