3L6T

Crystal Structure of an N-terminal Mutant of the Plasmid pCU1 TraI Relaxase Domain

3L6T の概要

• エントリーDOI: 10.2210/pdb3l6t/pdb
• 関連するPDBエントリー: 3L57
• 分子名称: Mobilization protein TraI, CITRIC ACID, 1,2-ETHANEDIOL, ... (9 entities in total)
• 機能のキーワード: trwc superfamily of relaxase enzymes, conjugative relaxase, mob class relaxase, conjugal nickase, hydrolase, histidine triad, huh+h motif
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 70404.78

構造登録者

Redinbo, M.R.,Nash, R.P. (登録日: 2009-12-24, 公開日: 2010-05-19, 最終更新日: 2023-09-06)

主引用文献

Nash, R.P.,Habibi, S.,Cheng, Y.,Lujan, S.A.,Redinbo, M.R.
The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1.
Nucleic Acids Res., 38:5929-5943, 2010

PubMed Abstract: Bacteria expand their genetic diversity, spread antibiotic resistance genes, and obtain virulence factors through the highly coordinated process of conjugative plasmid transfer (CPT). A plasmid-encoded relaxase enzyme initiates and terminates CPT by nicking and religating the transferred plasmid in a sequence-specific manner. We solved the 2.3 A crystal structure of the relaxase responsible for the spread of the resistance plasmid pCU1 and determined its DNA binding and nicking capabilities. The overall fold of the pCU1 relaxase is similar to that of the F plasmid and plasmid R388 relaxases. However, in the pCU1 structure, the conserved tyrosine residues (Y18,19,26,27) that are required for DNA nicking and religation were displaced up to 14 A out of the relaxase active site, revealing a high degree of mobility in this region of the enzyme. In spite of this flexibility, the tyrosines still cleaved the nic site of the plasmid's origin of transfer, and did so in a sequence-specific, metal-dependent manner. Unexpectedly, the pCU1 relaxase lacked the sequence-specific DNA binding previously reported for the homologous F and R388 relaxase enzymes, despite its high sequence and structural similarity with both proteins. In summary, our work outlines novel structural and functional aspects of the relaxase-mediated conjugative transfer of plasmid pCU1.

PubMed: 20448025
DOI: 10.1093/nar/gkq303

実験手法

X-RAY DIFFRACTION (1.93 Å)