Crystallization and preliminary X-ray diffraction studies of the catalytic domain of a novel chitinase, a member of GH family 23, from the moderately thermophilic bacterium sp. A-471

好熱菌 sp. A-471由来新規キチナーゼ触媒ドメインの結晶化及びX線回折研究

岡崎 伸生; 有森 貴夫; 中澤 昌美*; 宮武 和孝*; 上田 光宏*; 玉田 太郎

Okazaki, Nobuo; Arimori, Takao; Nakazawa, Masami*; Miyatake, Kazutaka*; Ueda, Mitsuhiro*; Tamada, Taro

Chitinase from the moderately thermophilic bacterium sp. A-471 (Ra-ChiC) is divided into two domains: a chitin-binding domain (residues 36-80) and a catalytic domain (residues 103-252). Although the catalytic domain of Ra-ChiC has homology to goose-type lysozyme, Ra-ChiC does not show lysozyme activity but does show chitinase activity. The catalytic domain with part of an interdomain loop (Ra-ChiC) was crystallized under several different conditions using polyethylene glycol as a precipitant. The crystals diffracted to 1.85 resolution and belonged to space group 622 or 622, with unit-cell parameters = = 100, = 243 . The calculated Matthews coefficient was approximately 3.2, 2.4 or 1.9 Da assuming the presence of three, four or five Ra-ChiC molecules in the asymmetric unit, respectively.