[Protein S3 fragments neighboring mRNA during elongation and translation termination on the human ribosome].
Protein S3 fragments were determined that crosslink to modified mRNA analogues in positions +5 to +12 relative to the first nucleotide in the P-site binding codon in model complexes mimicking states of ribosomes at the elongation and translation termination steps. The mRNA analogues contained a Phe codon UUU/UUC at the 5'-termini that could predetermine the position of the tRNA(Phe) on the ribosome by the location of P-site binding and perfluorophenylazidobenzoyl group at a nucleotide in various positions 3' of the UUU/UUC codon. The crosslinked S3 protein was isolated from 80S ribosomal complexes irradiated with mild UV light and subjected to cyanogen bromide-induced cleavage at methionine residues with subsequent identification of the crosslinked oligopeptides. An analysis of the positions of modified oligopeptides resulting from the cleavage showed that, in dependence on the positions of modified nucleotides in the mRNA analogue, the crosslinking sites were found in the N-terminal half of the protein (fragment 2-127) and/or in the C-terminal fragment 190-236; the latter reflects a new peculiarity in the structure of the mRNA binding center in the ribosome, unknown to date. The results of crosslinking did not depend on the type of A-site codon or on the presence of translation termination factor eRF1.
Khaĭrulina
Iu S
IuS
Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090 Russia.
Molotkov
M V
MV
Bulygin
K N
KN
Graĭfer
D M
DM
Ven'yaminova
A G
AG
Frolova
L Iu
LIu
Stahl
J
J
Karpova
G G
GG
D003062:Codon / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D010441:Peptide Chain Elongation, Translational / Q000502:physiology*; D010443:Peptide Chain Termination, Translational / Q000502:physiology*; D010454:Peptide Termination Factors / Q000737:chemistry / Q000378:metabolism; D012346:RNA, Transfer, Amino Acyl / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000378:metabolism; D012270:Ribosomes; D014466:Ultraviolet Rays
D003062:Codon; C489002:ETF1 protein, human; D009842:Oligopeptides; D010454:Peptide Termination Factors; D012346:RNA, Transfer, Amino Acyl; D012269:Ribosomal Proteins; C044152:ribosomal protein S3