3j8c

Model of the human eIF3 PCI-MPN octamer docked into the 43S EM mapModel of the human eIF3 PCI-MPN octamer docked into the 43S EM map

3j8c, resolution 11.60Å Show:Asymmetric Unit Biological Assembly Structural highlights 3j8c is a 8 chain structure with sequence from Homo sapiens. This structure supersedes the now removed PDB entry 3j7k. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 3j8b, 4u1d, 4u1c, 4lct, 4b4t, 4o8x, 1rz4, 3chm, 3j47 Activity: Ubiquitinyl hydrolase 1, with EC number 3.4.19.12 Experimental data: Check Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Publication Abstract from PubMed Eukaryotic translation initiation begins with assembly of a 43S preinitiation complex. First, methionylated initiator methionine transfer RNA (Met-tRNAi(Met)), eukaryotic initiation factor (eIF) 2, and guanosine triphosphate form a ternary complex (TC). The TC, eIF3, eIF1, and eIF1A cooperatively bind to the 40S subunit, yielding the 43S preinitiation complex, which is ready to attach to messenger RNA (mRNA) and start scanning to the initiation codon. Scanning on structured mRNAs additionally requires DHX29, a DExH-box protein that also binds directly to the 40S subunit. Here, we present a cryo-electron microscopy structure of the mammalian DHX29-bound 43S complex at 11.6 A resolution. It reveals that eIF2 interacts with the 40S subunit via its alpha subunit and supports Met-tRNAi(Met) in an unexpected P/I orientation (eP/I). The structural core of eIF3 resides on the back of the 40S subunit, establishing two principal points of contact, whereas DHX29 binds around helix 16. The structure provides insights into eukaryote-specific aspects of translation, including the mechanism of action of DHX29. Structure of the mammalian ribosomal 43S preinitiation complex bound to the scanning factor DHX29.,Hashem Y, des Georges A, Dhote V, Langlois R, Liao HY, Grassucci RA, Hellen CU, Pestova TV, Frank J Cell. 2013 May 23;153(5):1108-19. doi: 10.1016/j.cell.2013.04.036. PMID:23706745 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Eukaryotic initiation factor 3D structures