2hf6 | pdb_00002hf6
Solution structure of human zeta-COP
Structural highlights
Function[COPZ1_HUMAN] 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. In mammals, the coatomer can only be recruited by membranes associated to ADP-ribosylation factors (ARFs), which are small GTP-binding proteins; the complex also influences the Golgi structural integrity, as well as the processing, activity, and endocytic recycling of LDL receptors (By similarity). The zeta subunit may be involved in regulating the coat assembly and, hence, the rate of biosynthetic protein transport due to its association-dissociation properties with the coatomer complex. 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 PubMedCOP-I-coated vesicles are protein and lipid carriers that mediate intra-Golgi transport and transport from the cis-Golgi complex to the endoplasmic reticulum in cells. The coatomer of the vesicles coat is comprised of seven subunits: alpha-COP, epsilon-COP, beta'-COP, beta-COP, gamma-COP, delta-COP, and zeta-COP. Here we report the solution structure of a truncated form (residues 1-149; zeta-COP149) of human zeta-COP (total 177 residues). It is the first three-dimensional structure of a "core" subunit of the COP I F-subcomplex. The structure of zeta-COP149 mainly consists of a disordered N-terminal tail, a five-stranded antiparallel beta-sheet, a two-stranded antiparallel beta-sheet, and five alpha-helices. The global folding of zeta-COP149 is very similar to the crystal structures of AP1-sigma1 and AP2-sigma2, directly demonstrating the structural similarity between the "core" subunits of the COP I F-subcomplex and adaptor protein complexes. Through structural comparison and mutagenesis study, we have also demonstrated that the heterodimers of zeta-COP149 and gamma-COP have packing interfaces and relative subunit orientations similar to those of AP2-sigma2 and AP2-alpha heterodimers. These results provide direct evidence supporting the previous proposal that the COP I F-subcomplex and adaptor protein complexes have similar tertiary and quaternary structures. Solution structure of human zeta-COP: direct evidences for structural similarity between COP I and clathrin-adaptor coats.,Yu W, Lin J, Jin C, Xia B J Mol Biol. 2009 Mar 6;386(4):903-12. Epub 2009 Jan 10. PMID:19167404[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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