Roxana Nechifor

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We have trapped elongation factor G (EF-G) from Escherichia coli in six, functionally defined states, representing intermediates in its unidirectional catalytic cycle, which couples GTP hydrolysis to tRNA-mRNA translocation in the ribosome. By probing EF-G with trypsin in each state, we identified a substantial conformational change involving its conserved(More)
The antibiotic fusidic acid potently inhibits bacterial translation (and cellular growth) by lodging between domains I and III of elongation factor G (EF-G) and preventing release of EF-G from the ribosome. We examined the functions of key amino acid residues near the active site of EF-G that interact with fusidic acid and regulate hydrolysis of GTP.(More)
Protein L7/L12 of the bacterial ribosome plays an important role in activating the GTP hydrolytic activity of elongation factor G (EF-G), which promotes ribosomal translocation during protein synthesis. Previously, we cross-linked L7/L12 from two residues (209 and 231) flanking alpha-helix AG' in the G' subdomain of Escherichia coli EF-G. Here we report(More)
A conserved translation factor, known as EF-G in bacteria, promotes the translocation of tRNA and mRNA in the ribosome during protein synthesis. Here, EF-G.ribosome complexes in two intermediate states, before and after mRNA translocation, have been probed with hydroxyl radicals generated from free Fe(II)-EDTA. Before mRNA translocation and GTP hydrolysis,(More)
Elongation factor G (EF-G) promotes the translocation of tRNA and mRNA in the central cavity of the ribosome following the addition of each amino acid residue to a growing polypeptide chain. tRNA/mRNA translocation is coupled to GTP hydrolysis, catalyzed by EF-G and activated by the ribosome. In this study we probed EF-G interactions with ribosomal proteins(More)
Ribosomal protection proteins (RPPs) confer bacterial resistance to tetracycline by releasing this antibiotic from ribosomes stalled in protein synthesis. RPPs share structural similarity to elongation factor G (EF-G), which promotes ribosomal translocation during normal protein synthesis. We constructed and functionally characterized chimeric proteins of(More)
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