skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1

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 {angstrom} 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 {angstrom} 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 transfermore » of plasmid pCU1.« less

Authors:
; ; ; ;  [1]
  1. UNC
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE
OSTI Identifier:
1002530
Resource Type:
Journal Article
Journal Name:
Nucleic Acids Res.
Additional Journal Information:
Journal Volume: 38; Journal Issue: (17) ; 2010; Journal ID: ISSN 0305-1048
Country of Publication:
United States
Language:
ENGLISH
Subject:
36 MATERIALS SCIENCE; ANTIBIOTICS; BACTERIA; CRYSTAL STRUCTURE; DNA; ENZYMES; FLEXIBILITY; FUNCTIONALS; GENES; GENETICS; ORIGIN; PLASMIDS; PROTEINS; RESIDUES; TYROSINE; VIRULENCE

Citation Formats

Nash, Rebekah Potts, Habibi, Sohrab, Cheng, Yuan, Lujan, Scott A, and Redinbo, Matthew. The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1. United States: N. p., 2010. Web. doi:10.1093/nar/gkq303.
Nash, Rebekah Potts, Habibi, Sohrab, Cheng, Yuan, Lujan, Scott A, & Redinbo, Matthew. The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1. United States. https://doi.org/10.1093/nar/gkq303
Nash, Rebekah Potts, Habibi, Sohrab, Cheng, Yuan, Lujan, Scott A, and Redinbo, Matthew. 2010. "The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1". United States. https://doi.org/10.1093/nar/gkq303.
@article{osti_1002530,
title = {The mechanism and control of DNA transfer by the conjugative relaxase of resistance plasmid pCU1},
author = {Nash, Rebekah Potts and Habibi, Sohrab and Cheng, Yuan and Lujan, Scott A and Redinbo, Matthew},
abstractNote = {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 {angstrom} 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 {angstrom} 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.},
doi = {10.1093/nar/gkq303},
url = {https://www.osti.gov/biblio/1002530}, journal = {Nucleic Acids Res.},
issn = {0305-1048},
number = (17) ; 2010,
volume = 38,
place = {United States},
year = {Mon Nov 15 00:00:00 EST 2010},
month = {Mon Nov 15 00:00:00 EST 2010}
}