D-arabinose synthesis in TB using Azorhizobium as a tool

描述（由申请人提供）：结核病是艾滋病的一种主要机会性疾病，可加重疾病的病程。此外，结核病威胁艾滋病护理人员和接触者，并滋生耐药的M。结核因此，新的药物，具体为M。肺结核是帮助控制艾滋病流行所必需的。D-阿拉伯糖的形成是结核分枝杆菌的一个理想的药物靶点，因为它对结核分枝杆菌是必需的和特异的。结核病和D-阿拉伯糖在人类中没有发现。对M. PI已经确定了结核病的致病基因;然而，尚未成功鉴定出这些基因。因此，这项艾滋病FIRCA研究的目的是确定M。结核病基因负责D-阿拉伯糖的合成，并决定编码蛋白质的功能。使这项研究和合作成为可能的突破是外国合作者Holsters博士在Azorhizobium caulinodans中发现了合成D-阿拉伯糖的四个基因（A. caulinodans是自然界中除分枝杆菌外极少数合成D-阿拉伯糖的其它生物之一）。此外，她还发现了M. 结核病与A.茎瘤基因。因此，我们建议确定的D-阿拉伯糖合成基因在M。结核病通过互补A. caulinodans与M.结核病候选基因此外，我们建议通过鉴定这些特定基因敲除菌株中的D-阿拉伯糖形成前体来确定每个基因产物的功能。caulinodans的表达和酶活性测定。结核病和A. caulinodans基因在E.杆菌A. caulinodans和D-阿拉伯糖前体的研究将主要在国外地点进行，而所需的放射性前体和分枝杆菌的生物化学技术和遗传学将来自美国地点。

DESCRIPTION (provided by applicant): Tuberculosis is a major opportunistic disease of AIDS which exacerbates the course of the illness. Furthermore, tuberculosis threatens AIDS caretakers and contacts and breeds drugs resistant strains of M. tuberculosis. Hence, new drugs, specific for M. tuberculosis are needed to help control the AIDS epidemic. D-arabinose formation is an ideal TB drug target as it is essential and specific for M. tuberculosis and D-arabinose is not found in humans. The pathway for formation of D-arabinose in M. tuberculosis has been determined by the PI; however, the genes have not been successfully identified. Thus, the purpose of this AIDS-FIRCA research is to identify the M. tuberculosis genes responsible for the synthesis of D-arabinose and determine the function of the encoded proteins. The breakthrough that has made both this research and the collaboration possible is the finding by the foreign collaborator, Dr. Holsters, of four genes in Azorhizobium caulinodans that synthesize D-arabinose (A. caulinodans is one of the very few other organisms in nature that synthesize D-arabinose besides mycobacteria). Furthermore, she discovered the existence of genes in M. tuberculosis homologous to three of the A. caulinodans genes. Therefore, we propose to identify the D-arabinose synthetic genes in M. tuberculosis by complementing specific gene knockout mutants of A. caulinodans with M. tuberculosis gene candidates. Further we propose to determine the function of each gene product by the identification of D-arabinose formation precursors in these specific gene knockout strains of A. caulinodans and by expression and enzymatic assay of the M. tuberculosis and A. caulinodans genes in E. coli. The genetics on A. caulinodans and the searches for D-arabinose precursors will be mostly performed at the foreign site while needed radioactive precursors and biochemical techniques and genetics in mycobacteria will come from the American site.