The mechanism of leukocytolysis and hemolysis of the Staphylococcal leukocidin and gamma-hemolysin

众所周知，在生物学功能上表现出大体相似的蛋白质具有彼此相似的初级结构。然而，近年来有报道称，即使是初级结构不同的蛋白质，其生物学功能和三维结构也相同。以葡萄球菌通道形成毒素为例。金黄色葡萄球菌将白细胞素和溶血素作为水溶性单体分泌到培养基中。杀白细胞素和r -HL分别含有LukF和LukS以及LukF和Hlg2（或H γ H）两种独立的协同蛋白成分。在人多形核白细胞膜和红细胞膜中，杀白细胞素的LukF和LukS以及γ -HL的LukF和Hlg2聚集成环状复合物，其中LukF与LukS或Hlg2的摩尔比均为1:1。在每种情况下，跨膜孔的功能直径为2.1-2.5 nm；更多的，这导致溶解各自的目标细胞。白细胞杀死素和γ -HL的细胞特异性分别由LukS和Hlg2决定。尽管LukS和Hlg2氨基酸序列之间的总体一致性为72%，但各自的细胞特异性是严格定义的。在科学研究资助(B)支持的一年内，我们澄清了以下证据。[1]从丝裂霉素c诱导的金黄色葡萄球菌V8 （ATCC 49775）中分离的噬菌体phiPVL基因组中存在pton - valentine leukocidin （PVL）基因[lukS-PV-lukF-PV] [Kaneko等，1997]。Biosci。Biotechnol。生物化学学报，2009,32(2):481 - 481。在本研究中，我们分析了phiPVL基因组的完整核苷酸序列，并确定了phiPVL特异位点整合到宿主染色体所需的att位点（attL、attR和attB）。[II]葡萄球菌γ溶血素Hlg2特异性功能所必需的最小片段的确定：Hlg2的5-残基K^<23>RLA^<127>是葡萄球菌γ溶血素Hlg2特异性功能所必需的最小片段。[III]苏氨酸246残基为葡萄球菌白细胞素LukS特异性功能的蛋白激酶a磷酸化位点的最小片段鉴定：确定了白细胞素LukS特异性功能的最小片段。我们得出结论，5残基片段I^< 2424> K^< 2424> R^< 2424> S^< 2424> T^< 2424>是LukS的关键片段，负责葡萄球菌杀白细胞素的LukS功能。[IV]蛋白激酶A磷酸化LukS对葡萄球菌嗜白素对人多形核白细胞的LukS特异性功能至关重要[V]葡萄球菌LukF的晶体结构描述了跨膜通道形成时的构象变化。少

It is well known that the proteins which show gross similarities in their biological function(s) have primary structures which are similar to each other. However, recently even proteins which show dissimilarity in primary structures have been reported to have identical biological functions and the three-dimensional structures. The Staphylococcal channel-forming toxins are taken as an example. Staphylococcus aureus secretes leukocidin and gamma-hemolysin gamma -HL) into a culture medium as water soluble monomers. Leukocidin and r -HL contain two separate and synergistic protein components, LukF and LukS, and LukF and Hlg2 (or H gamma H), respectively. LukF and LukS of leukocidin, and LukF and Hlg2 of gamma -HL assemble into a ring-shaped complexes, in which the molar ratios of LukF to LukS or Hlg2, respectively are both 1 : 1, within human polymorphonuclear leukocyte membranes and erythrocyte membranes. In each case a transmembrane pore results with a functional diameter of 2.1-2.5 nm ; … More this leads to lyse the respective target cell. The cell specificities of leukocidin and gamma -HL are determined by LukS and Hlg2, respectively. Despite the 72% overall identity between the LukS and Hlg2 aminoacid sequences, the respective cell specificities are strictly defined, Within the year suported by Grant-in-Aid for Scientific Research (B), we clarified the following evidences.[I] The staphylococcal Panton-Valentine leukocidin (PVL) genes, [lukS-PV-lukF-PV] exist on the genome of a temperate bacteriophage phiPVL isolated from mitomycin C-induced Staphylococcus aureus V8 (ATCC 49775) [Kaneko et al., 1997. Biosci. Biotechnol. Biochem. 61, 1960-l962]. In this study, the complete nucleotide sequence of the phiPVL genome was analyzed, and the att sites (attL, attR, and attB) required for site-specific integration of phiPVL into the host chromosome were also determined.[II] Identification of the minimum segment essential for the Hlg2-specific function of staphylococcal gamma Hemolysin : The 5-residue K^<23>RLA^<127> of Hlg2 is the minimum segment essential for the Hlg2-specificfunction of staphylococcal gamma-hemolysin.[III] Identification of the minimum segment in which threonine 246 residue is a phosphorylation site by protein kinase A for the LukS-specific function of staphylococcal leukocidin : The minimum segment responsible for the LukS specific funcion of leukocidin was identified. We conclude that the 5-residue segment I^<242>K^<243>R^<244>S^<245>T^<246> is pivotal segment of LukS responsible for the LukS-function of the staphylococcal leukocidin.[IV] The Phosphorylation of LukS by Protein Kinase A is Crucial for the LukS-Specific Function of the Staphylococcal Leukocidin on Human Polymorphonuclear Leukocytes[V] Crystal structure of staphylococcal LukF delineates conformational changes accompaning formation of a transmembrane channel. Less