TY - JOUR

T1 - Exploring contacts of eRF1 with the 3′-terminus of the P site tRNA and mRNA stop signal in the human ribosome at various translation termination steps

AU - Bulygin, Konstantin N.

AU - Graifer, Dmitri M.

AU - Hountondji, Codjo

AU - Frolova, Ludmila Yu

AU - Karpova, Galina G.

N1 - Publisher Copyright: © 2017 Elsevier B.V.

PY - 2017/7/1

Y1 - 2017/7/1

N2 - Here we employed site-directed cross-linking with the application of tRNA and mRNA analogues bearing an oxidized ribose at the 3′-terminus to investigate mutual arrangement of the main components of translation termination complexes formed on the human 80S ribosome bound with P site deacylated tRNA using eRF1•eRF3•GTP or eRF1 alone. In addition, we applied a model complex obtained in the same way with eRF1•eRF3•GMPPNP. We found that eRF3 content in the complexes with GTP and GMPPNP is similar, proving that eRF3 does not leave the ribosome after GTP hydrolysis. Our cross-linking data allowed determining locations of the 3′-terminus of the P site tRNA relatively the eRF1 M domain and of the mRNA stop signal toward the N domain and the ribosomal decoding site at the nucleotide-peptide resolution level. Our results indicate that locations of these components do not change after peptide release up to post-termination pre-recycling state, and the positioning of the mRNA stop signal remains similar to that when eRF1 recognizes it. Besides, we found that in all the complexes studied eRF1 shielded the N-terminal part of ribosomal protein eS30 from the interaction with the nucleotide adjacent to stop codon observed with pre-termination ribosome free of eRFs. Altogether, our findings brought important information on contacts of the key structural elements of eRF1, tRNA and mRNA in the ribosomal complexes including those mimicking different translation termination steps, thereby providing a deeper understanding of molecular mechanisms underlying events occurring in the course of protein synthesis termination in mammals.

AB - Here we employed site-directed cross-linking with the application of tRNA and mRNA analogues bearing an oxidized ribose at the 3′-terminus to investigate mutual arrangement of the main components of translation termination complexes formed on the human 80S ribosome bound with P site deacylated tRNA using eRF1•eRF3•GTP or eRF1 alone. In addition, we applied a model complex obtained in the same way with eRF1•eRF3•GMPPNP. We found that eRF3 content in the complexes with GTP and GMPPNP is similar, proving that eRF3 does not leave the ribosome after GTP hydrolysis. Our cross-linking data allowed determining locations of the 3′-terminus of the P site tRNA relatively the eRF1 M domain and of the mRNA stop signal toward the N domain and the ribosomal decoding site at the nucleotide-peptide resolution level. Our results indicate that locations of these components do not change after peptide release up to post-termination pre-recycling state, and the positioning of the mRNA stop signal remains similar to that when eRF1 recognizes it. Besides, we found that in all the complexes studied eRF1 shielded the N-terminal part of ribosomal protein eS30 from the interaction with the nucleotide adjacent to stop codon observed with pre-termination ribosome free of eRFs. Altogether, our findings brought important information on contacts of the key structural elements of eRF1, tRNA and mRNA in the ribosomal complexes including those mimicking different translation termination steps, thereby providing a deeper understanding of molecular mechanisms underlying events occurring in the course of protein synthesis termination in mammals.

KW - CCA end of tRNA

KW - Human ribosome

KW - mRNA stop signal

KW - Release factors eRF1 and eRF3

KW - Ribosomal decoding site

KW - Site-directed cross-linking

KW - Translation termination

KW - Protein Binding/genetics

KW - Ribosomal Proteins/genetics

KW - Humans

KW - Ribosomes/genetics

KW - RNA, Messenger/genetics

KW - Peptide Termination Factors/genetics

KW - Peptide Chain Termination, Translational/genetics

KW - Codon, Terminator/genetics

KW - Protein Biosynthesis/genetics

KW - RNA, Transfer/genetics

UR - http://www.scopus.com/inward/record.url?scp=85018376058&partnerID=8YFLogxK

U2 - 10.1016/j.bbagrm.2017.04.004

DO - 10.1016/j.bbagrm.2017.04.004

M3 - Article

C2 - 28457996

AN - SCOPUS:85018376058

VL - 1860

SP - 782

EP - 793

JO - Biochimica et Biophysica Acta - Gene Regulatory Mechanisms

JF - Biochimica et Biophysica Acta - Gene Regulatory Mechanisms

SN - 1874-9399

IS - 7

ER -