Structural highlights
Function
EIF3B_HUMAN Component of the eukaryotic translation initiation factor 3 (eIF-3) complex, which is required for several steps in the initiation of protein synthesis. The eIF-3 complex associates with the 40S ribosome and facilitates the recruitment of eIF-1, eIF-1A, eIF-2:GTP:methionyl-tRNAi and eIF-5 to form the 43S preinitiation complex (43S PIC). The eIF-3 complex stimulates mRNA recruitment to the 43S PIC and scanning of the mRNA for AUG recognition. The eIF-3 complex is also required for disassembly and recycling of post-termination ribosomal complexes and subsequently prevents premature joining of the 40S and 60S ribosomal subunits prior to initiation.[1]
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 PubMed
Mammalian eIF3 is a 700-kDa multiprotein complex essential for initiation of protein synthesis in eukaryotic cells. It consists of 13 subunits (eIF3a to -m), among which eIF3b serves as a major scaffolding protein. Here we report the solution structure of the N-terminal RNA recognition motif of human eIF3b (eIF3b-RRM) determined by NMR spectroscopy. The structure reveals a noncanonical RRM with a negatively charged surface in the beta-sheet area contradictory with potential RNA binding activity. Instead, eIF3j, which is required for stable 40 S ribosome binding of the eIF3 complex, specifically binds to the rear alpha-helices of the eIF3b-RRM, opposite to its beta-sheet surface. Moreover, we identify that an N-terminal 69-amino acid peptide of eIF3j is sufficient for binding to eIF3b-RRM and that this interaction is essential for eIF3b-RRM recruitment to the 40 S ribosomal subunit. Our results provide the first structure of an important subdomain of a core eIF3 subunit and detailed insights into protein-protein interactions between two eIF3 subunits required for stable eIF3 recruitment to the 40 S subunit.
Structure of eIF3b RNA recognition motif and its interaction with eIF3j: structural insights into the recruitment of eIF3b to the 40 S ribosomal subunit.,ElAntak L, Tzakos AG, Locker N, Lukavsky PJ J Biol Chem. 2007 Mar 16;282(11):8165-74. Epub 2006 Dec 26. PMID:17190833[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Chaudhuri J, Chakrabarti A, Maitra U. Biochemical characterization of mammalian translation initiation factor 3 (eIF3). Molecular cloning reveals that p110 subunit is the mammalian homologue of Saccharomyces cerevisiae protein Prt1. J Biol Chem. 1997 Dec 5;272(49):30975-83. PMID:9388245
- ↑ ElAntak L, Tzakos AG, Locker N, Lukavsky PJ. Structure of eIF3b RNA recognition motif and its interaction with eIF3j: structural insights into the recruitment of eIF3b to the 40 S ribosomal subunit. J Biol Chem. 2007 Mar 16;282(11):8165-74. Epub 2006 Dec 26. PMID:17190833 doi:10.1074/jbc.M610860200
