Carrica Mariela del Carmen, Craig Patricio Oliver, Alonso Silvia del Valle, Goldbaum Fernando Alberto, Cravero Silvio Lorenzo
Instituto de Biotecnología, CICVyA, INTA, Los reseros y las cabanas s/n, Castelar, Buenos Aires, Agentina.
Biochemistry. 2008 Aug 5;47(31):8165-75. doi: 10.1021/bi800462y. Epub 2008 Jul 11.
The bacterial genus Brucella consists of a group of facultative intracellular pathogens which produces abortion and infertility in animals and a chronic debilitating febrile illness in humans. BMFP is a basic protein of Brucella abortus that belongs to a highly conserved group of homologue proteins of unknown structure and function in proteobacteria (COG2960). In this study, we report the structural and biochemical characterization of this protein. We found that BMFP has two structural domains: a carboxyl-terminal coiled-coil domain through which the protein self-associates as a trimer and a natively disordered amino-terminal domain which has propensity to adopt an amphipathic alpha-helical structure. This natively unfolded domain undergoes a structural rearrangement from unfolded to alpha-helix in the presence of high ionic strength, acidic pH, detergents, and phospholipid vesicles. Moreover, we demonstrated that the interaction of BMFP with phospholipid vesicles promotes in vitro membrane fusion. These results contribute to the elucidation of the structural and functional properties of this protein and its homologues present in most proteobacteria.
布鲁氏菌属细菌是一类兼性细胞内病原体，可导致动物流产和不育，并使人类患上慢性衰弱性发热疾病。BMFP是流产布鲁氏菌的一种碱性蛋白，属于变形菌中一组结构和功能未知的高度保守的同源蛋白（COG2960）。在本研究中，我们报告了该蛋白的结构和生化特征。我们发现BMFP有两个结构域：一个羧基末端卷曲螺旋结构域，该蛋白通过此结构域以三聚体形式自缔合；以及一个天然无序的氨基末端结构域，该结构域倾向于形成两亲性α-螺旋结构。在高离子强度、酸性pH值、去污剂和磷脂囊泡存在的情况下，这个天然未折叠的结构域会发生从未折叠到α-螺旋的结构重排。此外，我们证明了BMFP与磷脂囊泡的相互作用促进了体外膜融合。这些结果有助于阐明该蛋白及其在大多数变形菌中存在的同源蛋白的结构和功能特性。
