1yz7

Crystal structure of a C-terminal segment of the alpha subunit of aIF2 from Pyrococcus abyssi

spinqualitylabelsall models 1yz7, resolution 2.26Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1yz7 is a 1 chain structure with sequence from "pyrococcus_abyssi"_erauso_et_al._1993 "pyrococcus abyssi" erauso et al. 1993. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 1yz6 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [IF2A_PYRAB] eIF-2 functions in the early steps of protein synthesis by forming a ternary complex with GTP and initiator tRNA (By similarity). 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 Eukaryotic and archaeal initiation factor 2 (e- and aIF2, respectively) are heterotrimeric proteins (alphabetagamma) supplying the small subunit of the ribosome with methionylated initiator tRNA. The gamma subunit forms the core of the heterotrimer. It resembles elongation factor EF1-A and ensures interaction with Met-tRNA(i)(Met). In the presence of the alpha subunit, which is composed of three domains, the gamma subunit expresses full tRNA binding capacity. This study reports the crystallographic structure of the intact aIF2alpha subunit from the archaeon Pyrococcus abyssi and that of a derived C-terminal fragment containing domains 2 and 3. The obtained structures are compared with those of N-terminal domains 1 and 2 of yeast and human eIF2alpha and with the recently determined NMR structure of human eIF2alpha. We show that the three-domain organization in the alpha subunit is conserved in archaea and eukarya. Domains 1 and 2 form a rigid body linked to a mobile third domain. Sequence comparisons establish that the most conserved regions in the aIF2alpha polypeptide lie at opposite sides of the protein, within domain 1 and domain 3, respectively. These two domains are known to exhibit RNA binding capacities. We propose that domain 3, which is known to glue the alpha subunit onto the gamma subunit, participates in Met-tRNA(i)(Met) binding while domain 1 recognizes either rRNA or mRNA on the ribosome. Thereby, the observed structural mobility within the e- and aIF2alpha molecules would be an integral part of the biological function of this subunit in the heterotrimeric e- and aIF2alphabetagamma factors. Structure-function relationships of the intact aIF2alpha subunit from the archaeon Pyrococcus abyssi.,Yatime L, Schmitt E, Blanquet S, Mechulam Y Biochemistry. 2005 Jun 21;44(24):8749-56. PMID:15952781 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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