2ihr
From Proteopedia
RF2 of Thermus thermophilus
Structural highlights
FunctionRF2_THET8 Peptide chain release factor 2 directs the termination of translation in response to the peptide chain termination codons UGA and UAA (Probable). In endogenous ribosomes interacts with P-site tRNA and 23S rRNA (PubMed:18988853, PubMed:20421507). In the presence of truncated mRNA in the 70S ribosome, ArfA and RF2 interact such that the GGQ peptide hydrolysis motif of RF2 rises into the peptidyl-transferase center and releases the ribosome (By similarity). Recruited to stalled E.coli 70S ribosomes by E.coli ArfA, but cannot be functionally accomodated in the peptidyl-transferase center (PubMed:27934701, PubMed:28077875). Note T.thermophilus probably does not encode arfA (Ref.1).[UniProtKB:P07012][1] [2] [3] [4] [5] [UniProtKB:P07012] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedProkaryotic class I release factors (RFs) respond to mRNA stop codons and terminate protein synthesis. They interact with the ribosomal decoding site and the peptidyl-transferase centre bridging these 75 A distant ribosomal centres. For this an elongated RF conformation, with partially unfolded core domains II.III.IV is required, which contrasts the known compact RF crystal structures. The crystal structure of Thermus thermophilus RF2 was determined and compared with solution structure of T. thermophilus and Escherichia coli RF2 by microcalorimetry, circular dichroism spectroscopy and small angle X-ray scattering. The structure of T. thermophilus RF2 in solution at 20 degrees C is predominantly compact like the crystal structure. Thermodynamic analysis point to an initial melting of domain I, which is independent from the melting of the core. The core domains II.III.IV melt cooperatively at the respective physiological temperatures for T. thermophilus and E. coli. Thermodynamic analyses and the X-ray scattering results for T. thermophilus RF2 in solution suggest that the compact conformation of RF2 resembles a physiological state in absence of the ribosome. Release factors 2 from Escherichia coli and Thermus thermophilus: structural, spectroscopic and microcalorimetric studies.,Zoldak G, Redecke L, Svergun DI, Konarev PV, Voertler CS, Dobbek H, Sedlak E, Sprinzl M Nucleic Acids Res. 2007;35(4):1343-53. Epub 2007 Feb 1. PMID:17272297[6] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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