2ATQ

RB69 single-stranded DNA binding protein-DNA polymerase fusion

2ATQ の概要

• エントリーDOI: 10.2210/pdb2atq/pdb
• 分子名称: DNA polymerase, gp32, GUANOSINE-5'-DIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: dna polymerase, palm domain, fingers domain, thumb domain, single-stranded dna binding protein, ob-fold, transferase-dna binding protein complex, transferase/dna binding protein
• 由来する生物種: Enterobacteria phage RB69; 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 131392.27

構造登録者

Sun, S.,Geng, L.,Shamoo, Y. (登録日: 2005-08-25, 公開日: 2006-05-09, 最終更新日: 2023-08-23)

主引用文献

Sun, S.,Geng, L.,Shamoo, Y.
Structure and enzymatic properties of a chimeric bacteriophage RB69 DNA polymerase and single-stranded DNA binding protein with increased processivity.
Proteins, 65:231-238, 2006

PubMed Abstract: In vivo, replicative DNA polymerases are made more processive by their interactions with accessory proteins at the replication fork. Single-stranded DNA binding protein (SSB) is an essential protein that binds tightly and cooperatively to single-stranded DNA during replication to remove adventitious secondary structures and protect the exposed DNA from endogenous nucleases. Using information from high resolution structures and biochemical data, we have engineered a functional chimeric enzyme of the bacteriophage RB69 DNA polymerase and SSB with substantially increased processivity. Fusion of RB69 DNA polymerase with its cognate SSB via a short six amino acid linker increases affinity for primer-template DNA by sixfold and subsequently increases processivity by sevenfold while maintaining fidelity. The crystal structure of this fusion protein was solved by a combination of multiwavelength anomalous diffraction and molecular replacement to 3.2 A resolution and shows that RB69 SSB is positioned proximal to the N-terminal domain of RB69 DNA polymerase near the template strand channel. The structural and biochemical data suggest that SSB interactions with DNA polymerase are transient and flexible, consistent with models of a dynamic replisome during elongation.

PubMed: 16881051
DOI: 10.1002/prot.21088

実験手法

X-RAY DIFFRACTION (3.2 Å)