Recycling of the Posttermination Complexes of Mycobacterium smegmatis and Escherichia coli Ribosomes Using Heterologous Factors

Seshadri, Anuradha and Singh, Sadananda N and Varshney, Umesh (2010) Recycling of the Posttermination Complexes of Mycobacterium smegmatis and Escherichia coli Ribosomes Using Heterologous Factors. In: Journal of Molecular Biology, 401 (5). pp. 854-865. (In Press)

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Abstract

In eubacteria, ribosome recycling factor (RRF) and elongation factor G (EFG) function together to dissociate posttermination ribosomal complexes. Earlier studies, using heterologous factors from Mycobacterium tuberculosis in Escherichia coli revealed that specific interactions between RRF and EFG are crucial for their function in ribosome recycling. Here, we used translation factors from E.coli,Mycobacterium smegmatis and M. tuberculosis, and polysomes from E. coli and M. smegmatis, and employed in vivo and in vitro experiments to further understand the role of EFG in ribosome recycling. We show thatE. coli EFG (EcoEFG) recycles E. coli ribosomes with E. coli REF (EcoRRF), but not with mycobacterial RRFs. Also, EcoEFG fails to recycle M. smegmatis ribosomes with either EcoRRF or mycobacterial RRFs. On the other hand, mycobacterial EFGs recycle both E. coli and M. smegmatis ribosomes with either of the RRFs. These observations suggest that EFG establishes distinct interactions with REF and the ribosome to carry out ribosome recycling. Furthermore, the EFG chimeras generated by swapping domains betweenmycobacterial EFGs and EcoEFG suggest that while the residues needed to specify the EFG interaction with REF arelocated in domains IV and V. those required to specify its interaction with the ribosome are located throughout the molecule. (C) 2010 Elsevier Ltd. All rights reserved.

Item Type:	Journal Article
Publication:	Journal of Molecular Biology
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Mycobacterium tuberculosis; chimeric EFG; RRF; distinct interactions.
Department/Centre:	Division of Biological Sciences > Microbiology & Cell Biology
Date Deposited:	15 Sep 2010 11:39
Last Modified:	19 Sep 2010 06:16
URI:	http://eprints.iisc.ac.in/id/eprint/32131

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