4j82 | pdb_00004j82

Crystal structure of beta'-COP/Insig-2 complex

spinqualitylabelsall models 4j82, resolution 1.46Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4j82 is a 4 chain structure with sequence from Saccharomyces cerevisiae. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Related: 4j73, 4j77, 4j78, 4j79, 4j81, 4j84, 4j86, 4j87, 4j8b, 4j8g Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [COPB2_YEAST] The coatomer is a cytosolic protein complex that binds to dilysine motifs and reversibly associates with Golgi non-clathrin-coated vesicles, which further mediate biosynthetic protein transport from the ER, via the Golgi up to the trans Golgi network. Coatomer complex is required for budding from Golgi membranes, and is essential for the retrograde Golgi-to-ER transport of dilysine-tagged proteins. [INSI2_HUMAN] Mediates feedback control of cholesterol synthesis by controlling SCAP and HMGCR. Functions by blocking the processing of sterol regulatory element-binding proteins (SREBPs). Capable of retaining the SCAP-SREBF2 complex in the ER thus preventing it from escorting SREBPs to the Golgi. Seems to regulate the ubiquitin-mediated proteasomal degradation of HMGCR. Publication Abstract from PubMed Cytoplasmic dilysine motifs on transmembrane proteins are captured by coatomer alpha-COP and beta'-COP subunits and packaged into COPI-coated vesicles for Golgi-to-ER retrieval. Numerous ER/Golgi proteins contain K(x)Kxx motifs, but the rules for their recognition are unclear. We present crystal structures of alpha-COP and beta'-COP bound to a series of naturally occurring retrieval motifs-encompassing KKxx, KxKxx and non-canonical RKxx and viral KxHxx sequences. Binding experiments show that alpha-COP and beta'-COP have generally the same specificity for KKxx and KxKxx, but only beta'-COP recognizes the RKxx signal. Dilysine motif recognition involves lysine side-chain interactions with two acidic patches. Surprisingly, however, KKxx and KxKxx motifs bind differently, with their lysine residues transposed at the binding patches. We derive rules for retrieval motif recognition from key structural features: the reversed binding modes, the recognition of the C-terminal carboxylate group which enforces lysine positional context, and the tolerance of the acidic patches for non-lysine residues. Rules for the recognition of dilysine retrieval motifs by coatomer.,Ma W, Goldberg J EMBO J. 2013 Mar 12. doi: 10.1038/emboj.2013.41. PMID:23481256 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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