Conformational transitions in the γ subunit of the archaeal translation initiation factor 2. (1st March 2014)

• Record Type: Journal Article
• Authors: Nikonov, Oleg; Stolboushkina, Elena; Arkhipova, Valentina; Kravchenko, Olesya; Nikonov, Stanislav; Garber, Maria
• Is Part Of: Acta crystallographica. Volume 70:Part 3(2014:Mar.)
• Page Start: 658
• Page End: 667
• Publication Date: 2014-03-01
• Subjects: Biomolecules -- Structure -- Periodicals; Physical biochemistry -- Periodicals; X-ray crystallography -- Periodicals; Crystallography -- Periodicals; 572
• DOI: 10.1107/S1399004713032240
• Languages: English
• ISSNs: 0907-4449

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>In 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 eIF2γ–GDP–P_i (inorganic phosphate) active state. Here, four high‐resolution crystal structures of aIF2γ from <italic>Sulfolobus solfataricus</italic> are reported: aIF2γ–GDPCP (a nonhydrolyzable GTP analogue), aIF2γ–GDP–formate (in which a formate ion possibly mimics P_i), aIF2γ–GDP and nucleotide‐free aIF2γ. The structures describe the different states of aIF2γ and demonstrate the conformational transitions that take place in the aIF2γ `life cycle'.</p> </abstract>