title: The archaeal elongation factor 1alpha bound to GTP forms a ternary complex with eubacterial and eukaryal aminoacyl-tRNA.
abstract: The archaeal Sulfolobus solfataricus elongation factor 1alpha (SsEF-1alpha) bound to GTP or to its analogue guanyl-5'-yl imido diphosphate [Gpp(NH)p] formed a ternary complex with either Escherichia coli Val-tRNAVal or Saccharomyces cerevisiae Phe-tRNAPhe as demonstrated by gel-shift and gel-filtration experiments. Evidence of such an interaction also came from the observation that SsEF-1alphaz.rad;Gpp(NH)p was able to display a protective effect against either the spontaneous deacylation or the digestion of aminoacyl-tRNA by RNase A. Protection against the deacylation of aminoacyl-tRNA allowed evaluatation of the affinity of SsEF-1alphaz. rad;Gpp(NH)p for both aminoacyl-tRNAs used. The K'd values of the ternary complex containing S. cerevisiae Phe-tRNAPhe or E. coli Val-tRNAVal were 0.3 microM and 4.4 microM, respectively. In both cases, the affinity of SsEF-1alphaz.rad;Gpp(NH)p for aminoacyl-tRNA was three orders of magnitude lower than that of the homologous eubacterial ternary complexes, but comparable with the affinity shown by the ternary complex involving eukaryal EF-1alpha [Negrutskii, B.S. & El'skaya, A.V. (1998) Prog. Nucleic Acids Res. 60, 47-77]. As already observed with eukaryal EF-1alpha, SsEF-1alpha in its GDP-bound form was also able to protect the ester bond of aminoacyl-tRNA, even though with a 10-fold lower efficiency compared with SsEF-1alphaz.rad;Gpp(NH)p. The overall results indicated that the archaeal elongation factor 1alpha shares several properties with eukaryal EF-1alpha but not with eubacterial EF-Tu.
authors.affiliation: Dipartimento di Biochimica e Biotecnologie Mediche, Università di Napoli Federico II, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Raimo
authors.forename: M
authors.initials: M
authors.lastname: Masullo
authors.forename: B
authors.initials: B
authors.lastname: Lombardo
authors.forename: V
authors.initials: V
authors.lastname: Bocchini
mesh_terms: D019843:Archaeal Proteins / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D019143:Evolution, Molecular; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D046911:Macromolecular Substances; D020648:Peptide Elongation Factor 1 / Q000378:metabolism*; D019642:RNA, Archaeal / Q000378:metabolism*; D012329:RNA, Bacterial / Q000378:metabolism*; D012331:RNA, Fungal / Q000378:metabolism*; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012259:Ribonuclease, Pancreatic / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013045:Species Specificity; D016944:Sulfolobus / Q000378:metabolism
chemical_list: D019843:Archaeal Proteins; D046911:Macromolecular Substances; D020648:Peptide Elongation Factor 1; D019642:RNA, Archaeal; D012329:RNA, Bacterial; D012331:RNA, Fungal; D012346:RNA, Transfer, Amino Acyl; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D012259:Ribonuclease, Pancreatic