PMID: 12554937

Authors:

Verboven C, Bogaerts I, Waelkens E, Rabijns A, Van Baelen H, Bouillon R, De Ranter C

Title:

Actin-DBP: the perfect structural fit?

Journal:

Acta Crystallogr D Biol Crystallogr. 2003 Feb;59(Pt 2):263-73. Epub 2003, Jan 23.

Abstract:

The multifunctional vitamin D binding protein (DBP) is an actin-sequestering protein present in blood. The crystal structure of the actin-DBP complex was determined at 2.4 A resolution. DBP binds to actin subdomains 1 and 3 and occludes the cleft at the interface between these subdomains. Most remarkably, DBP demonstrates an unusually large actin-binding interface, far exceeding the binding-interface areas reported for other actin-binding proteins such as profilin, DNase I and gelsolin. The fast-growing side of actin monomers is blocked completely through a perfect structural fit with DBP, demonstrating how DBP effectively interferes with actin-filament formation. It establishes DBP as the hitherto best actin-sequestering protein and highlights its key role in suppressing and preventing extracellular actin polymerization.