title: Preliminary X-ray crystallographic analysis of the catalytic domain of prophenoloxidase activating factor-I.
abstract: Clip-domain serine proteases (SPs) have been identified in invertebrates as crucial enzymes that are involved in diverse extracellular signalling pathways. Prophenoloxidase (proPO) activating factor-I (PPAF-I), a catalytically active clip-domain SP, cleaves proPO. To date, no crystal structures of a catalytically active clip-domain SP have been determined. Here, the results of crystallization and preliminary X-ray analysis of the SP domain of PPAF-I are reported. The crystal of the PPAF-I SP domain was obtained using the hanging-drop vapour-diffusion method in a precipitant solution containing 0.15 M lithium sulfate, 30% polyethylene glycol 4000 and 0.1 M Tris-HCl pH 8.0. The crystal diffracts X-rays to 1.7 angstroms resolution using a synchrotron-radiation source. The crystal belongs to space group P2(1)2(1)2(1), with one molecule in the asymmetric unit and unit-cell parameters a = 38.3, b = 53.3, c = 116.6 angstroms, alpha = beta = gamma = 90 degrees. A molecular-replacement solution has been found using kallikrein as a starting model, resulting in an interpretable electron-density map.
authors.affiliation: College of Pharmacy and Research Institute for Drug Development, Pusan National University, Jangjeon-dong, Geumjeong-gu, Busan 609-735, South Korea.
authors.forename: Shunfu
authors.initials: S
authors.lastname: Piao
authors.forename: Ji Young
authors.initials: JY
authors.lastname: Jung
authors.forename: Ji Won
authors.initials: JW
authors.lastname: Park
authors.forename: Jaewon
authors.initials: J
authors.lastname: Lee
authors.forename: Bok Leul
authors.initials: BL
authors.lastname: Lee
authors.forename: Nam Chul
authors.initials: NC
authors.lastname: Ha
mesh_terms: D000595:Amino Acid Sequence; D020134:Catalytic Domain; D004156:Catechol Oxidase / Q000378:metabolism*; D017124:Conserved Sequence; D018360:Crystallography, X-Ray; D004792:Enzyme Precursors / Q000378:metabolism*; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D004792:Enzyme Precursors; C038451:pro-phenoloxidase; D004156:Catechol Oxidase; D012697:Serine Endopeptidases; C022435:prephenoloxidase-activating enzyme