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C‐terminal domains of human translation termination factors eRF1 and eRF3 mediate their in vivo interaction
Author(s) -
Merkulova Tatyana I.,
Frolova Lyudmila Y.,
Lazar Monique,
Camonis Jacques,
Kisselev Lev L.
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)01669-x
Subject(s) - release factor , gtpase , ribosome , chemistry , translation (biology) , microbiology and biotechnology , stop codon , biology , biochemistry , amino acid , gene , messenger rna , rna
At the termination step of protein synthesis, hydrolysis of the peptidyl‐tRNA is jointly catalysed at the ribosome by the termination codon and the polypeptide release factor (eRF1 in eukaryotes). eRF1 forms in vivo and in vitro a stable complex with release factor eRF3, an eRF1‐dependent and ribosome‐dependent GTPase. The role of the eRF1⋅eRF3 complex in translation remains unclear. We have undertaken a systematic analysis of the interactions between the human eRF1 and eRF3 employing a yeast two‐hybrid assay. We show that the N‐terminal parts of eRF1 (positions 1–280) and of eRF3 (positions 1–477) are either not involved or non‐essential for binding. Two regions in each factor are critical for mutual binding: positions 478–530 and 628–637 of eRF3 and positions 281–305 and 411–415 of eRF1. The GTP binding domain of eRF3 is not involved in complex formation with eRF1. The GILRY pentamer (positions 411–415) conserved in eukaryotes and archaebacteria is critical for eRF1's ability to stimulate eRF3 GTPase. The human eRF1 lacking 22 C‐terminal amino acids remains active as a release factor and promotes an eRF3 GTPase activity whereas C‐terminally truncated eRF3 is inactive as a GTPase.