1kl9
From Proteopedia
Crystal structure of the N-terminal segment of Human eukaryotic initiation factor 2alpha
Structural highlights
Function[IF2A_HUMAN] Functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA. This complex binds to a 40S ribosomal subunit, followed by mRNA binding to form a 43S preinitiation complex. Junction of the 60S ribosomal subunit to form the 80S initiation complex is preceded by hydrolysis of the GTP bound to eIF-2 and release of an eIF-2-GDP binary complex. In order for eIF-2 to recycle and catalyze another round of initiation, the GDP bound to eIF-2 must exchange with GTP by way of a reaction catalyzed by eIF-2B. 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 PubMedEukaryotic translation initiation factor 2alpha (eIF2alpha) is a member of the eIF2 heterotrimeric complex that binds and delivers Met-tRNA(i)(Met) to the 40 S ribosomal subunit in a GTP-dependent manner. Phosphorylation/dephosphorylation of eIF2alpha at Ser-51 is the major regulator of protein synthesis in eukaryotic cells. Here, we report the first structural analysis on eIF2, the three-dimensional structure of a 22-kDa N-terminal portion of human eIF2alpha by x-ray diffraction at 1.9 A resolution. This structure contains two major domains. The N terminus is a beta-barrel with five antiparallel beta-strands in an oligonucleotide binding domain (OB domain) fold. The phosphorylation site (Ser-51) is on the loop connecting beta3 and beta4 in the OB domain. A helical domain follows the OB domain, and the first helix has extensive interactions, including a disulfide bridge, to fix its orientation with respect to the OB domain. The two domains meet along a negatively charged groove with highly conserved residues, indicating a likely site for protein-protein interaction. Crystal structure of the N-terminal segment of human eukaryotic translation initiation factor 2alpha.,Nonato MC, Widom J, Clardy J J Biol Chem. 2002 May 10;277(19):17057-61. Epub 2002 Feb 21. PMID:11859078[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Human | Large Structures | Clardy, J | Nonato, M C | Widom, J | Helical domain | Ob fold | Translation
