4m0l
Gamma subunit of the translation initiation factor 2 from Sulfolobus solfataricus complexed with GDPGamma subunit of the translation initiation factor 2 from Sulfolobus solfataricus complexed with GDP
Structural highlights
FunctionIF2G_SACS2 eIF-2 functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA.[HAMAP-Rule:MF_00119] Publication Abstract from PubMedIn eukaryotes and archaea, the heterotrimeric translation initiation factor 2 (e/aIF2) is pivotal for the delivery of methionylated initiator tRNA (Met-tRNA(i)) to the ribosome. It acts as a molecular switch that cycles between inactive (GDP-bound) and active (GTP-bound) states. Recent studies show that eIF2 can also exist in a long-lived eIF2gamma-GDP-P(i) (inorganic phosphate) active state. Here, four high-resolution crystal structures of aIF2gamma from Sulfolobus solfataricus are reported: aIF2gamma-GDPCP (a nonhydrolyzable GTP analogue), aIF2gamma-GDP-formate (in which a formate ion possibly mimics P(i)), aIF2gamma-GDP and nucleotide-free aIF2gamma. The structures describe the different states of aIF2gamma and demonstrate the conformational transitions that take place in the aIF2gamma `life cycle'. Conformational transitions in the gamma subunit of the archaeal translation initiation factor 2.,Nikonov O, Stolboushkina E, Arkhipova V, Kravchenko O, Nikonov S, Garber M Acta Crystallogr D Biol Crystallogr. 2014 Mar;70(Pt 3):658-67. doi:, 10.1107/S1399004713032240. Epub 2014 Feb 15. PMID:24598735[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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