3chk

Calcium bound structure of alpha-14 giardin

spinqualitylabelsall models 3chk, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3chk is a 1 chain structure with sequence from Giardia lamblia. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CA Related: 3chj, 3chl Gene: Alpha-14 (Giardia lamblia) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT 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 Alpha-14 giardin (annexin E1), a member of the alpha giardin family of annexins, has been shown to localize to the flagella of the intestinal protozoan parasite Giardia lamblia. Alpha giardins show a common ancestry with the annexins, a family of proteins most of which bind to phospholipids and cellular membranes in a Ca(2+)-dependent manner and are implicated in numerous membrane-related processes including cytoskeletal rearrangements and membrane organization. It has been proposed that alpha-14 giardin may play a significant role during the cytoskeletal rearrangement during differentiation of Giardia. To gain a better understanding of alpha-14 giardin's mode of action and its biological role, we have determined the three-dimensional structure of alpha-14 giardin and its phospholipid-binding properties. Here, we report the apo crystal structure of alpha-14 giardin determined in two different crystal forms as well as the Ca(2+)-bound crystal structure of alpha-14 giardin, refined to 1.9, 1.6 and 1.65 A, respectively. Although the overall fold of alpha-14 giardin is similar to that of alpha-11 giardin, multiwavelength anomalous dispersion phasing was required to solve the alpha-14 giardin structure, indicating significant structural differences between these two members of the alpha giardin family. Unlike most annexin structures, which typically possess N-terminal domains, alpha-14 giardin is composed of only a core domain, followed by a C-terminal extension that may serve as a ligand for binding to cytoskeletal protein partners in Giardia. In the Ca(2+)-bound structure we detected five bound calcium ions, one of which is a novel, highly coordinated calcium-binding site not previously observed in annexin structures. This novel high-affinity calcium-binding site is composed of seven protein donor groups, a feature rarely observed in crystal structures. In addition, phospholipid-binding assays suggest that alpha-14 giardin exhibits calcium-dependent binding to phospholipids that coordinate cytoskeletal disassembly/assembly during differentiation of the parasite. Apo and calcium-bound crystal structures of cytoskeletal protein alpha-14 giardin (annexin E1) from the intestinal protozoan parasite Giardia lamblia.,Pathuri P, Nguyen ET, Ozorowski G, Svard SG, Luecke H J Mol Biol. 2009 Jan 30;385(4):1098-112. Epub 2008 Nov 20. PMID:19046974 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Annexin 3D structures

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