Lafaye Céline, Iwema Thomas, Ferrer Jean-Luc, Kroll J Simon, Griat Mickael, Serre Laurence
Laboratoire des Protéines Membranaires, Institut de Biologie Structurale, CEA/CNRS/Université Joseph Fourier, 41 Rue Jules Horowitz, 38027 Grenoble CEDEX 01, France.
Acta Crystallogr Sect F Struct Biol Cryst Commun. 2008 Feb 1;64(Pt 2):111-4. doi: 10.1107/S1744309108000754. Epub 2008 Jan 31.
Bacterial virulence depends on the correct folding of surface-exposed proteins, a process that is catalyzed by the thiol-disulfide oxidoreductase DsbA, which facilitates the synthesis of disulfide bonds in Gram-negative bacteria. Uniquely among bacteria, the Neisseria meningitidis genome possesses three genes encoding active DsbAs: DsbA1, DsbA2 and DsbA3. DsbA1 and DsbA2 have been characterized as lipoproteins involved in natural competence and in host-interactive biology, while the function of DsbA3 remains unknown. In an attempt to shed light on the reason for this multiplicity of dsbA genes, the three enzymes from N. meningitidis have been purified and crystallized in the presence of high concentrations of ammonium sulfate. The best crystals were obtained using DsbA1 and DsbA3; they belong to the orthorhombic and tetragonal systems and diffract to 1.5 and 2.7 A resolution, respectively.
细菌毒力取决于表面暴露蛋白的正确折叠，这一过程由硫醇-二硫键氧化还原酶DsbA催化，该酶促进革兰氏阴性菌中二硫键的合成。在细菌中独一无二的是，脑膜炎奈瑟菌基因组拥有三个编码活性DsbA的基因：DsbA1、DsbA2和DsbA3。DsbA1和DsbA2已被鉴定为参与自然感受态和宿主相互作用生物学的脂蛋白，而DsbA3的功能仍然未知。为了阐明dsbA基因这种多样性的原因，已对来自脑膜炎奈瑟菌的三种酶进行了纯化，并在高浓度硫酸铵存在的情况下进行了结晶。使用DsbA1和DsbA3获得了最佳晶体；它们分别属于正交晶系和四方晶系，衍射分辨率分别为1.5埃和2.7埃。
