4KJZ

Crystal Structure of Thermus Thermophilus IF2, Apo and GDP-bound Forms (2-474)

4KJZ の概要

• エントリーDOI: 10.2210/pdb4kjz/pdb
• 分子名称: Translation initiation factor IF-2, GUANOSINE-5'-DIPHOSPHATE (3 entities in total)
• 機能のキーワード: translation initiation factor/if2 superfamily, gtpase, gtp, translation
• 由来する生物種: Thermus thermophilus
• 細胞内の位置: Cytoplasm: P48515
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 210149.70

構造登録者

Eiler, D.R.,Lin, J.,Steitz, T.A. (登録日: 2013-05-04, 公開日: 2013-09-11, 最終更新日: 2023-09-20)

主引用文献

Eiler, D.,Lin, J.,Simonetti, A.,Klaholz, B.P.,Steitz, T.A.
Initiation factor 2 crystal structure reveals a different domain organization from eukaryotic initiation factor 5B and mechanism among translational GTPases.
Proc.Natl.Acad.Sci.USA, 110:15662-15667, 2013

PubMed Abstract: The initiation of protein synthesis uses initiation factor 2 (IF2) in prokaryotes and a related protein named eukaryotic initiation factor 5B (eIF5B) in eukaryotes. IF2 is a GTPase that positions the initiator tRNA on the 30S ribosomal initiation complex and stimulates its assembly to the 50S ribosomal subunit to make the 70S ribosome. The 3.1-Å resolution X-ray crystal structures of the full-length Thermus thermophilus apo IF2 and its complex with GDP presented here exhibit two different conformations (all of its domains except C2 domain are visible). Unlike all other translational GTPases, IF2 does not have an effecter domain that stably contacts the switch II region of the GTPase domain. The domain organization of IF2 is inconsistent with the "articulated lever" mechanism of communication between the GTPase and initiator tRNA binding domains that has been proposed for eIF5B. Previous cryo-electron microscopy reconstructions, NMR experiments, and this structure show that IF2 transitions from being flexible in solution to an extended conformation when interacting with ribosomal complexes.

PubMed: 24029018
DOI: 10.1073/pnas.1309360110

実験手法

X-RAY DIFFRACTION (2.8 Å)