RRC ID 3253
Author Singh NS, Das G, Seshadri A, Sangeetha R, Varshney U.
Title Evidence for a role of initiation factor 3 in recycling of ribosomal complexes stalled on mRNAs in Escherichia coli.
Journal Nucleic Acids Res.
Abstract Specific interactions between ribosome recycling factor (RRF) and elongation factor-G (EFG) mediate disassembly of post-termination ribosomal complexes for new rounds of initiation. The interactions between RRF and EFG are also important in peptidyl-tRNA release from stalled pre-termination complexes. Unlike the post-termination complexes (harboring deacylated tRNA), the pre-termination complexes (harboring peptidyl-tRNA) are not recycled by RRF and EFG in vitro, suggesting participation of additional factor(s) in the process. Using a combination of biochemical and genetic approaches, we show that, (i) Inclusion of IF3 with RRF and EFG results in recycling of the pre-termination complexes; (ii) IF3 overexpression in Escherichia coli LJ14 rescues its temperature sensitive phenotype for RRF; (iii) Transduction of infC135 (which encodes a functionally compromised IF3) in E.coli LJ14 generates a 'synthetic severe' phenotype; (iv) The infC135 and frr1 (containing an insertion in the RRF gene promoter) alleles synergistically rescue a temperature sensitive mutation in peptidyl-tRNA hydrolase in E.coli; and (v) IF3 facilitates ribosome recycling by Thermus thermophilus RRF and E.coli EFG in vivo and in vitro. These lines of evidence clearly demonstrate the physiological importance of IF3 in the overall mechanism of ribosome recycling in E.coli.
Volume 33(17)
Pages 5591-601
Published 2005
DOI 10.1093/nar/gki864
PII 33/17/5591
PMID 16199751
PMC PMC1240113
MeSH Alleles Escherichia coli / genetics* Escherichia coli / metabolism Escherichia coli Proteins / genetics Escherichia coli Proteins / physiology* Mutation Peptide Chain Initiation, Translational* Peptide Chain Termination, Translational Peptide Elongation Factor G / metabolism Phenotype Prokaryotic Initiation Factor-3 / genetics Prokaryotic Initiation Factor-3 / physiology* RNA, Messenger / metabolism Ribosomal Proteins / physiology Ribosomes / metabolism* Temperature
IF 11.147
Times Cited 22
Prokaryotes E. coli ME8568(HB101)