title: Site-directed mutagenesis of Arg58 and Asp86 of elongation factor Tu from Escherichia coli: effects on the GTPase reaction and aminoacyl-tRNA binding.
abstract: Elongation factor Tu from Escherichia coli was mutated separately at positions Asp86 and Arg58, in order to shed light both on the GTPase mechanism of elongation factor Tu and on the binding of aminoacyl-tRNA. In addition, the binding of guanine nucleotides was investigated by determination of the dissociation and association rate constants. The results imply that Arg58 is unimportant for the intrinsic GTPase mechanism and the binding of guanine nucleotides, whereas it is strongly involved in the binding of aminoacyl-tRNA and of the ribosome. Asp86 appears to be essential for the regulation of guanine-nucleotide affinities, and it may also play a role in the intrinsic GTPase mechanism.
authors.affiliation: Department of Chemistry, Arhus University, Denmark.
authors.forename: C R
authors.initials: CR
authors.lastname: Knudsen
authors.forename: B F
authors.initials: BF
authors.lastname: Clark
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001120:Arginine / Q000737:chemistry / Q000235:genetics; D001224:Aspartic Acid / Q000737:chemistry / Q000235:genetics; D001483:Base Sequence; D017931:DNA Primers / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism; D020963:GTP Phosphohydrolase-Linked Elongation Factors / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D010444:Peptide Elongation Factor Tu / Q000737:chemistry*; D011485:Protein Binding; D011728:Pyridones / Q000494:pharmacology; D012343:RNA, Transfer / Q000378:metabolism; D012360:RNA, Transfer, Phe / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D017931:DNA Primers; D011728:Pyridones; D012360:RNA, Transfer, Phe; D011994:Recombinant Proteins; D006153:Guanosine Diphosphate; D001224:Aspartic Acid; D006160:Guanosine Triphosphate; D012343:RNA, Transfer; D001120:Arginine; D020963:GTP Phosphohydrolase-Linked Elongation Factors; D010444:Peptide Elongation Factor Tu; C008536:mocimycin