Structural highlights
FunctionRS3_ECOLI Binds the lower part of the 30S subunit head. Binds mRNA in the 70S ribosome, positioning it for translation (By similarity).[1] Plays a role in mRNA unwinding by the ribosome, possibly by forming part of a processivity clamp.[2] Publication Abstract from PubMedThroughout the four phases of protein biosynthesis-initiation, elongation, termination, and recycling-the ribosome is controlled and regulated by at least one specified translational guanosine triphosphatase (trGTPase). Although the structural basis for trGTPase interaction with the ribosome has been solved for the last three steps of translation, the high-resolution structure for the key initiation trGTPase, initiation factor 2 (IF2), complexed with the ribosome, remains elusive. We determine the structure of IF2 complexed with a nonhydrolyzable guanosine triphosphate analog and initiator fMet-tRNAi (Met) in the context of the Escherichia coli ribosome to 3.7-A resolution using cryo-electron microscopy. The structural analysis reveals previously unseen intrinsic conformational modes of the 70S initiation complex, establishing the mutual interplay of IF2 and initator transfer RNA (tRNA) with the ribsosome and providing the structural foundation for a mechanistic understanding of the final steps of translation initiation. Structures of ribosome-bound initiation factor 2 reveal the mechanism of subunit association.,Sprink T, Ramrath DJ, Yamamoto H, Yamamoto K, Loerke J, Ismer J, Hildebrand PW, Scheerer P, Burger J, Mielke T, Spahn CM Sci Adv. 2016 Mar 4;2(3):e1501502. doi: 10.1126/sciadv.1501502. eCollection 2016 , Mar. PMID:26973877[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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