Crystal Structure of Human eIF3k
[EIF3K_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.
Publication Abstract from PubMed
eIF3k, the smallest subunit of eukaryotic initiation factor 3 (eIF3), interacts with several other subunits of eIF3 and the 40 S ribosomal subunit. eIF3k is conserved among high eukaryotes, including mammals, insects, and plants, and it is ubiquitously expressed in human tissues. Interestingly, eIF3k does not exist in some species of yeast. Thus, eIF3k may play a unique regulatory role in higher organisms. Here we report the crystal structure of human eIF3k, the first high-resolution structure of an eIF3 component. This novel structure contains two distinct domains, a HEAT (named for Huntington, elongation factor 3, A subunit of protein phosphatase 2A, target of rapamycin) repeat-like HAM (HEAT analogous motif) domain and a winged-helix-like WH domain. Through structural comparison and sequence conservation analysis, we show that eIF3k has three putative protein-binding surfaces and has potential RNA binding activity. The structure provides key information for understanding the structure and function of the eIF3 complex.
Crystal structure of human eIF3k, the first structure of eIF3 subunits.,Wei Z, Zhang P, Zhou Z, Cheng Z, Wan M, Gong W J Biol Chem. 2004 Aug 13;279(33):34983-90. Epub 2004 Jun 4. PMID:15180986
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.