Journal
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
Volume 109, Issue 52, Pages 21420-21425Publisher
NATL ACAD SCIENCES
DOI: 10.1073/pnas.1218581109
Keywords
-
Categories
Funding
- National Institutes of Health [AI095686]
Ask authors/readers for more resources
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 from Plasmodium vivax and Plasmodium falciparum in different crystal lattices. TRAP VWA domains adopt closed and open conformations, and bind a Mg2+ ion at a metal ion-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 beta ribbon and ordered TSR domain. The extensible beta 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 angstrom movement to the open conformation. The extensible beta ribbon and TSR domain overlap at a conserved interface. The VWA, extensible beta 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 stick-and-slip parasite motility and for development of sporozoite subunit vaccines.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available