@article {547201,
	title = {Shape Change in the Receptor for Gliding Motility in Plasmodium Sporozoites.},
	journal = {Proc Natl Acad Sci USA},
	volume = {109},
	number = {52},
	year = {2012},
	pages = {21420-21425},
	abstract = {Sporozoite gliding motility and invasion of mosquito and vertebrate host cells in malaria is mediated by thrombospondin repeat anonymous protein (TRAP). Tandem von Willebrand factor A (VWA) and thrombospondin type I repeat (TSR) domains in TRAP connect through proline-rich stalk, transmembrane, and cytoplasmic domains to the parasite actin-dependent motility apparatus. We crystallized fragments containing the VWA and TSR domains fromPlasmodium vivax\&nbsp;and\&nbsp;Plasmodium falciparum\&nbsp;in different crystal lattices. TRAP VWA domains adopt closed and open conformations, and bind a Mg2+\&nbsp;ion at a metal ion{\textendash}dependent adhesion site implicated in ligand binding. Metal ion coordination in the open state is identical to that seen in the open high-affinity state of integrin I domains. The closed VWA conformation associates with a disordered TSR domain. In contrast, the open VWA conformation crystallizes with an extensible β ribbon and ordered TSR domain. The extensible β ribbon is composed of disulfide-bonded segments N- and C-terminal to the VWA domain that are largely drawn out of the closed VWA domain in a 15 {\r A} movement to the open conformation. The extensible β ribbon and TSR domain overlap at a conserved interface. The VWA, extensible β ribbon, and TSR domains adopt a highly elongated overall orientation that would be stabilized by tensile force exerted across a ligand-receptor complex by the actin motility apparatus of the sporozoite. Our results provide insights into regulation of {\textquotedblleft}stick-and-slip{\textquotedblright} parasite motility and for development of sporozoite subunit vaccines.},
	author = {Song, G. and Koksal, A.C. and Lu, C. and Springer, T.A.}
}
