RRC ID 35601
Author Wei Y, Gao ZQ, Otsuka Y, Naka K, Yonesaki T, Zhang H, Dong YH.
Title Structure-function studies of Escherichia coli RnlA reveal a novel toxin structure involved in bacteriophage resistance.
Journal Mol. Microbiol.
Abstract Escherichia coli RnlA-RnlB is a newly identified toxin-antitoxin (TA) system that plays a role in bacteriophage resistance. RnlA functions as a toxin with mRNA endoribonuclease activity and the cognate antitoxin RnlB inhibits RnlA toxicity in E. coli cells. Interestingly, T4 phage encodes the antitoxin Dmd, which acts against RnlA to promote its own propagation, suggesting that RnlA-Dmd represents a novel TA system. Here, we have determined the crystal structure of RnlA refined to 2.10  (Dmd-binding domain), which is an organization not previously observed among known toxin structures. Small-angle X-ray scattering (SAXS) analysis revealed that RnlA forms a dimer in solution via interactions between the DBDs from both monomers. The in vitro and in vivo functional studies showed that among the three domains, only the DBD is responsible for recognition and inhibition by Dmd and subcellular location of RnlA. In particular, the helix located at the C-terminus of DBD plays a vital role in binding Dmd. Our comprehensive studies reveal the key region responsible for RnlA toxicity and provide novel insights into its structure-function relationship.
Volume 90(5)
Pages 956-65
Published 2013-12
DOI 10.1111/mmi.12409
PMID 24112600
MeSH Bacterial Toxins / chemistry* Binding Sites Crystallography, X-Ray Escherichia coli K12 / genetics* Escherichia coli K12 / metabolism* Escherichia coli Proteins / chemistry* Escherichia coli Proteins / metabolism Escherichia coli Proteins / physiology* Gene Expression Regulation, Bacterial Models, Molecular Protein Conformation Protein Multimerization Protein Structure, Secondary Protein Structure, Tertiary Recombinant Proteins / chemistry Scattering, Small Angle Sequence Homology, Amino Acid Viral Proteins / chemistry Viral Proteins / metabolism*
IF 3.816
Times Cited 11
Prokaryotes E. coli ?