title: The complex between ribosomal proteins and aminoacyl-tRNA: the interactions and hydrolytic activities are not confined to the proteins L2 and L16 of Escherichia coli ribosomes.
abstract: The capacity of some Escherichia coli (E. coli) ribosomal proteins to bind to tRNA and to hydrolyse their aminoacylated derivatives has been analysed. The following results were obtained: (1) The basic proteins L2, L16 and L33 and S20 bound f[3H]Met-tRNA to a similar extent as the total proteins from 30 S (TP30) or 50 S (TP50) when tested by nitrocellulose filtration, in contrast to the more acidic proteins L7/L12 and S8. (2) The proteins of the peptidyltransferase centre, L2 and L16, showed no distinct specificity, binding various charged tRNAs from E. coli and Saccharomyces cerevisiae (S. cerevisiae). (3) A number of isolated ribosomal proteins hydrolysed aminoacyl-tRNA as assessed by trichloroacetic acid precipitation, in contrast to the TP30 and TP50. (4) The loss of radiolabel from Ac[14C]Phe-tRNA and from [14C]tRNA in the presence of these proteins could not be prevented by RNasin, a ribonuclease inhibitor, whereas that mediated by a sample of non-RNase-free bovine serum albumin was inhibited. (5) When double-labelled, Ac[3H]Phe-[14C]tRNA was incubated with L2 both radiolabels were lost, indicating that this potential candidate for a peptidyltransferase enzyme does not specifically cleave the ester bond between the aminoacyl residue and the tRNA.
authors.affiliation: Max-Plank-Institut für Molekulare Genetik, Abt. Wittmann, Berlin, F.R.G.
authors.forename: V G
authors.initials: VG
authors.lastname: Sumpter
authors.forename: W P
authors.initials: WP
authors.lastname: Tate
authors.forename: K H
authors.initials: KH
authors.lastname: Nierhaus
mesh_terms: D004926:Escherichia coli / Q000378:metabolism*; D006868:Hydrolysis; D011485:Protein Binding; D012346:RNA, Transfer, Amino Acyl / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000302:isolation & purification / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism
chemical_list: D012346:RNA, Transfer, Amino Acyl; D012269:Ribosomal Proteins; C027937:ribosomal protein L16; C029466:ribosomal protein L2