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Role of the individual domains of translation termination factor eRF1 in GTP binding to eRF3
Author(s) -
Konko Artem V.,
Mitkevich Vladimir A.,
Dubovaya Vera I.,
Kolosov Peter M.,
Makarov Alexander A.,
Kisselev Lev L.
Publication year - 2007
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/prot.21544
Subject(s) - isothermal titration calorimetry , gtp' , gtpase , ribosome , translation (biology) , chemistry , stop codon , binding domain , microbiology and biotechnology , biochemistry , biology , biophysics , binding site , messenger rna , gene , rna , enzyme
Eukaryotic translational termination is triggered by polypeptide release factors eRF1, eRF3, and one of the three stop codons at the ribosomal A‐site. Isothermal titration calorimetry shows that (i) the separated MC, M, and C domains of human eRF1 bind to eRF3; (ii) GTP binding to eRF3 requires complex formation with either the MC or M + C domains; (iii) the M domain interacts with the N and C domains; (iv) the MC domain and Mg 2+ induce GTPase activity of eRF3 in the ribosome. We suggest that GDP binding site of eRF3 acquires an ability to bind γ‐phosphate of GTP if altered by cooperative action of the M and C domains of eRF1. Thus, the stop‐codon decoding is associated with the N domain of eRF1 while the GTPase activity of eRF3 is controlled by the MC domain of eRF1 demonstrating a substantial structural uncoupling of these two activities though functionally they are interrelated. Proteins 2008. © 2007 Wiley‐Liss, Inc.