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Specific interaction between the ribosome recycling factor and the elongation factor G from Mycobacterium tuberculosis mediates peptidyl‐tRNA release and ribosome recycling in Escherichia coli
Author(s) -
Rao Arasada Rajeswara,
Varshney Umesh
Publication year - 2001
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/20.11.2977
Subject(s) - biology , ribosome , escherichia coli , elongation factor , transfer rna , microbiology and biotechnology , mycobacterium tuberculosis , release factor , ef tu , biochemistry , rna , tuberculosis , gene , medicine , pathology
Once the translating ribosomes reach a termination codon, the nascent polypeptide chain is released in a factor‐dependent manner. However, the P‐site‐bound deacylated tRNA and the ribosomes themselves remain bound to the mRNA (post‐termination complex). The ribosome recycling factor (RRF) plays a vital role in dissociating this complex. Here we show that the Mycobacterium tuberculosis RRF ( Mtu RRF) fails to rescue Escherichia coli LJ14, a strain temperature‐sensitive for RRF ( frr ts ). More interestingly, co‐expression of M.tuberculosis elongation factor G ( Mtu EFG) with Mtu RRF rescues the frr ts strain of E.coli . The simultaneous expression of Mtu EFG is also needed to cause an enhanced release of peptidyl‐tRNAs in E.coli by Mtu RRF. These observations provide the first genetic evidence for a functional interaction between RRF and EFG. Both the in vivo and in vitro analyses suggest that RRF does not distinguish between the translating and terminating ribosomes for their dissociation from mRNA. In addition, complementation of E.coli PEM100 ( fusA ts ) with Mtu EFG suggests that the mechanism of RRF function is independent of the translocation activity of EFG.