Crystallization and preliminary X-ray characterization of the full-length bacteriophytochrome from the plant pathogen Xanthomonas campestris pv. campestris (Poster)

SEBASTIÁN KLINKE; LISANDRO OTERO; JIMENA RINALDI; SANTIAGO SOSA; FERNANDO A. GOLDBAUM; HERNÁN R. BONOMI

Sierra de la Ventana, Pcia Buenos Aires

Congreso; XLIII Reunión Anual de la Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica (SAB)

Phytochromes give rise to the largest photosensor family known to date. However, they are underrepresented in the Protein Data Bank. Plant, cyanobacterial, fungal and bacterial phytochromes share a canonical architecture consisting of an N-terminal photosensory module (PAS2-GAF-PHY domains) and a C-terminal variable output module. The bacterium Xanthomonas campestris pv. campestris, a worldwide agricultural pathogen, codes for a single bacteriophytochrome (XccBphP) that holds this canonical architecture, bearing a C-terminal PAS9 domain as the output module. Full-length XccBphP was cloned, expressed and purified to homogeneity by nickel-NTA affinity and size exclusion chromatography and then crystallized at room temperature bound to its cofactor biliverdin. A complete native X-ray diffraction dataset was collected to a maximum resolution of 3.25 A. Crystals belong to the space group P43212 with unit-cell parameters a = b = 103.94, c = 344.57 A, and a dimer in the asymmetric unit. Refinement is underway after solving the structure by molecular replacement [1].This work was supported by CONICET, ANPCyT, MINCyT and the SOLEIL Synchrotron (France).1-     Klinke, S. et al. & Bonomi, H.R. Acta Crystallographica Section F: Structural Biology Communications. 2014. In press.