title: Arginines 29 and 59 of elongation factor G are important for GTP hydrolysis or translocation on the ribosome.
abstract: GTP hydrolysis by elongation factor G (EF-G) is essential for the translocation step in protein elongation. The low intrinsic GTPase activity of EF-G is strongly stimulated by the ribosome. Here we show that a conserved arginine, R29, of Escherichia coli EF-G is crucial for GTP hydrolysis on the ribosome, but not for GTP binding or ribosome interaction, suggesting that it may be directly involved in catalysis. Another conserved arginine, R59, which is homologous to the catalytic arginine of G(alpha) proteins, is not essential for GTP hydrolysis, but influences ribosome binding and translocation. These results indicate that EF-G is similar to other GTPases in that an arginine residue is required for GTP hydrolysis, although the structural changes leading to GTPase activation are different.
authors.affiliation: Institutes of Physical Biochemistry and Molecular Biology, University of Witten/Herdecke, 58448 Witten, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Mohr
authors.forename: W
authors.initials: W
authors.lastname: Wintermeyer
authors.forename: M V
authors.initials: MV
authors.lastname: Rodnina
mesh_terms: D001120:Arginine / Q000378:metabolism*; D001692:Biological Transport; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D006868:Hydrolysis; D020653:Peptide Elongation Factor G / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D020653:Peptide Elongation Factor G; D006160:Guanosine Triphosphate; D001120:Arginine; D020558:GTP Phosphohydrolases