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Báo cáo khoa học: Interactions of elongation factor EF-P with the Escherichia coli ribosome

EF-P (eubacterial elongation factor P) is a highly conserved protein essen-tial for protein synthesis. We report that EF-P protects 16SrRNA near the G526 streptomycin and theS12 and mRNA binding sites (30ST-site). EF-P also protects domain V of the 23SrRNA proximal to the A-site (50ST-site) and more strongly the A-site of 70Sribosomes. | ỊFEBS Journal Interactions of elongation factor EF-P with the Escherichia coli ribosome Hiroyuki Aoki1 John Xu1 Andrew Emili2 John G. Chosay3 Ashkan Golshani4 and M. Clelia Ganoza1 1 University of Toronto C.H. Best Institute Canada 2 Terrance Donnelly Centre for Cellular and Biomolecular Research Donnelly CCBR Toronto Canada 3 Pfizer Pharmaceuticals Ann Arbor MI USA 4 Department of Biology Carleton University Ottawa Canada Keywords A-site eIF5A elongation factor EF-P ribosomes translocation Correspondence H. Aoki University of Toronto C.H. Best Institute 112 College Street Toronto Ontario M5G 1L6 Canada Fax 1 416 978 8528 Tel 1 416 978 8918 E-mail hiro.dr.aoki@utoronto.ca EF-P eubacterial elongation factor P is a highly conserved protein essential for protein synthesis. We report that EF-P protects 16S rRNA near the G526 streptomycin and the S12 and mRNA binding sites 30S T-site . EF-P also protects domain V of the 23S rRNA proximal to the A-site 50S T-site and more strongly the A-site of 70S ribosomes. We suggest that EF-P a may play a role in translational fidelity and b prevents entry of fMet-tRNA into the A-site enabling it to bind to the 50S P-site. We also report that EF-P promotes a ribosome-dependent accommodation of fMet-tRNA into the 70S P-site. Received 1 August 2007 revised 3 December 2007 accepted 10 December 2007 doi 10.1111 j.1742-4658.2007.06228.x In all cells ribosomes are inert in the absence of several proteins that promote each facet of protein synthesis. In eubacteria initiation factors IF-1 IF-2 IF-3 bind to the 30S subunit whereas elongation factors EF-Tu and EF-G and termination factors RF-1 RF-2 and RF-3 bind to 70S ribosomes. Reconstitution of synthesis using all of these homogeneous proteins revealed that they are insufficient for synthesis directed by a native mRNA and that several other proteins are required 1-6 . One of these proteins EF-P stimulates peptide bond synthesis by 70S ribosomes 1 2 6-8 . The gene encoding EF-P efp occurs at