title: Kinetics of the interactions between yeast elongation factors 1A and 1Balpha, guanine nucleotides, and aminoacyl-tRNA.
abstract: The interactions of elongation factor 1A (eEF1A) from Saccharomyces cerevisiae with elongation factor 1Balpha (eEF1Balpha), guanine nucleotides, and aminoacyl-tRNA were studied kinetically by fluorescence stopped-flow. eEF1A has similar affinities for GDP and GTP, 0.4 and 1.1 microm, respectively. Dissociation of nucleotides from eEF1A in the absence of the guanine nucleotide exchange factor is slow (about 0.1 s(-1)) and is accelerated by eEF1Balpha by 320-fold and 250-fold for GDP and GTP, respectively. The rate constant of eEF1Balpha binding to eEF1A (10(7)-10(8) M (-1) s(-1)) is independent of guanine nucleotides. At the concentrations of nucleotides and factors prevailing in the cell, the overall exchange rate is expected to be in the range of 6 s(-1), which is compatible with the rate of protein synthesis in the cell. eEF1A.GTP binds Phe-tRNA(Phe) with a K(d) of 3 nm, whereas eEF1A.GDP shows no significant binding, indicating that eEF1A has similar tRNA binding properties as its prokaryotic homolog, EF-Tu.
authors.affiliation: Institute of Physical Biochemistry, University of Witten/Herdecke, Stockumer Strasse 10, D-58448 Witten, Germany.
authors.forename: Kirill B
authors.initials: KB
authors.lastname: Gromadski
authors.forename: Tobias
authors.initials: T
authors.lastname: Schümmer
authors.forename: Anne
authors.initials: A
authors.lastname: Strømgaard
authors.forename: Charlotte R
authors.initials: CR
authors.lastname: Knudsen
authors.forename: Terri Goss
authors.initials: TG
authors.lastname: Kinzy
authors.forename: Marina V
authors.initials: MV
authors.lastname: Rodnina
mesh_terms: D006153:Guanosine Diphosphate / Q000737:chemistry / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D020648:Peptide Elongation Factor 1 / Q000737:chemistry / Q000378:metabolism*; D010444:Peptide Elongation Factor Tu; D011485:Protein Binding; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry / Q000378:metabolism*; D012360:RNA, Transfer, Phe / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology*; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D020648:Peptide Elongation Factor 1; D012346:RNA, Transfer, Amino Acyl; D012360:RNA, Transfer, Phe; D029701:Saccharomyces cerevisiae Proteins; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D010444:Peptide Elongation Factor Tu