title: [Mutation analysis of functional role of amino acid residues in domain IV of elongation factor G].
abstract: Seven variants of elongation factor G (EF-G) from Thermus thermophilus with mutations Glu494Ile, Gly495Asp, Lys496Ile, His509Leu, Lys564Ile and Tyr568Lys located in the beta-sheet of its domain IV and mutation Gly553Asp in a loop between domain III and IV were constructed using polymerase chain reaction. Functional tests demonstrated that only mutation Lys496Ile, located in the vicinity of the loop 501-504, inhibits translocation effectiveness, in the presence of the mutated EF-G. The functional analysis of all mutations constructed up to now in domain IV reveals that only those located in loops 501-504 and 573-578 markedly decrease the translocation activity of EF-G. These loops are located at the tip of domain IV and close to the decoding center of the 30S ribosomal subunit upon EF-G interaction with the ribosome. The functional role of EF-G and its domain IV in ribosomal translocation is discussed.
authors.forename: A A
authors.initials: AA
authors.lastname: Kovtun
authors.forename: A G
authors.initials: AG
authors.lastname: Minchenko
authors.forename: A T
authors.initials: AT
authors.lastname: Gudkov
mesh_terms: D019943:Amino Acid Substitution; D004252:DNA Mutational Analysis; D004926:Escherichia coli / Q000235:genetics; D006160:Guanosine Triphosphate / Q000378:metabolism; D010441:Peptide Chain Elongation, Translational; D020653:Peptide Elongation Factor G / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D011072:Poly U / Q000235:genetics / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism; D016963:Thermus thermophilus / Q000737:chemistry
chemical_list: D020653:Peptide Elongation Factor G; D011994:Recombinant Proteins; D011072:Poly U; D006160:Guanosine Triphosphate