In situ proteolysis, crystallization and preliminary X-ray diffraction analysis of a V_HH that binds listeria internalin B

V_HH R303 binds the Listeria virulence factor InlB. Crystals of R303 were obtained following in situ proteolysis with trypsin. Trypsin removed the flexible tag region of the protein, creating a homogeneous protein preparation. The crystals diffracted to 1.3 Å resolution.