2c4i | pdb_00002c4i

Crystal structure of engineered avidin

spinqualitylabelsall models 2c4i, resolution 1.95Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2c4i is a 1 chain structure with sequence from Gallus gallus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.95Å Ligands: BTN, SO4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function AVID_CHICK The biological function of avidin is not known. Forms a strong non-covalent specific complex with biotin (one molecule of biotin per subunit of avidin). Publication Abstract from PubMed Dual chain avidin (dcAvd) is an engineered avidin form, in which two circularly permuted chicken avidin monomers are fused into one polypeptide chain. DcAvd can theoretically form two different pseudotetrameric quaternary assemblies because of symmetry at the monomer-monomer interfaces. Here, our aim was to control the assembly of the quaternary structure of dcAvd. We introduced the mutation I117C into one of the circularly permuted domains of dcAvd and scanned residues along the 1-3 subunit interface of the other domain. Interestingly, V115H resulted in a single, disulfide locked quaternary assembly of dcAvd, whereas I117H could not guide the oligomerisation process even though it stabilised the protein. The modified dcAvd forms were found to retain their characteristic pseudotetrameric state both at high and low pH, and were shown to bind D-biotin at levels comparable to that of wild-type chicken avidin. The crystal structure of dcAvd-biotin complex at 1.95 Angstroms resolution demonstrates the formation of the functional dcAvd pseudotetramer at the atomic level and reveals the molecular basis for its special properties. Altogether, our data facilitate further engineering of the biotechnologically valuable dcAvd scaffold and gives insights into how to guide the quaternary structure assembly of oligomeric proteins. Controlling quaternary structure assembly: subunit interface engineering and crystal structure of dual chain avidin.,Hytonen VP, Horha J, Airenne TT, Niskanen EA, Helttunen KJ, Johnson MS, Salminen TA, Kulomaa MS, Nordlund HR J Mol Biol. 2006 Jun 23;359(5):1352-63. Epub 2006 May 6. PMID:16787776 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Avidin 3D structures

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