Pleiotropic effect of AccD5 and AccE5 depletion in acyl-coenzyme A carboxylase activity and in lipid biosynthesis in mycobacteria.
Pleiotropic effect of AccD5 and AccE5 depletion in acyl-coenzyme A carboxylase activity and in lipid biosynthesis in mycobacteria.
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DOI：
10.1371/journal.pone.0099853
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发表时间：
2014
期刊：
影响因子：
3.7
通讯作者：
Gramajo H
中科院分区：
文献类型：
--
作者：
Bazet Lyonnet B;Diacovich L;Cabruja M;Bardou F;Quémard A;Gago G;Gramajo H
分枝杆菌含有多种脂肪酸，用于生物合成几种复杂的细胞壁脂质，这些脂质与生物体抵抗宿主防御的能力有关。所有这些脂质的生物合成的构件由一组相当复杂的酰基辅酶A羧化酶（ACCases）提供，其亚基组成和在这些生物体中的作用尚未明确确定。先前的生化和结构研究提供了强有力的证据，来自结核分枝杆菌的ACCase 5由AccA 3、AccD 5和AccE 5亚基形成，并且该酶复合物羧酸化乙酰辅酶A和丙酰辅酶A，具有对最新底物的明显偏好。在这项工作中，我们使用了遗传学的方法来明确证明，accD 5和accE 5基因的产品是必不可少的耻垢分枝杆菌的生存能力。通过获得accD 5-accE 5操纵子的条件突变体，我们还证明了这种酶复合物的主要生理作用是为脂肪酸和分枝菌酸生物合成提供底物。此外，条件突变体的酶促和生化分析提供了强有力的证据，支持AccD 5和/或AccE 5在分枝菌酸缩合之前在长链酰基辅酶A的羧化中具有额外作用的观点。这些研究代表了更好地理解ACCases在分枝杆菌中的作用的重要一步，并证实ACCase 5是开发新的抗分枝杆菌药物的有趣靶点。
Mycobacteria contain a large variety of fatty acids which are used for the biosynthesis of several complex cell wall lipids that have been implicated in the ability of the organism to resist host defenses. The building blocks for the biosynthesis of all these lipids are provided by a fairly complex set of acyl-CoA carboxylases (ACCases) whose subunit composition and roles within these organisms have not yet been clearly established. Previous biochemical and structural studies provided strong evidences that ACCase 5 from Mycobacterium tuberculosis is formed by the AccA3, AccD5 and AccE5 subunits and that this enzyme complex carboxylates acetyl-CoA and propionyl-CoA with a clear substrate preference for the latest. In this work we used a genetic approach to unambiguously demonstrate that the products of both accD5 and accE5 genes are essential for the viability of Mycobacterium smegmatis. By obtaining a conditional mutant on the accD5-accE5 operon, we also demonstrated that the main physiological role of this enzyme complex was to provide the substrates for fatty acid and mycolic acid biosynthesis. Furthermore, enzymatic and biochemical analysis of the conditional mutant provided strong evidences supporting the notion that AccD5 and/or AccE5 have an additional role in the carboxylation of long chain acyl-CoA prior to mycolic acid condensation. These studies represent a significant step towards a better understanding of the roles of ACCases in mycobacteria and confirm ACCase 5 as an interesting target for the development of new antimycobacterial drugs.
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DOI：
10.1073/pnas.94.20.10955
发表时间：
1997-09-30
影响因子：
11.1
作者：
Pelicic, V;Jackson, M;Guilhot, C
通讯作者：
Guilhot, C
影响因子：
4.1
作者：
Forti, Francesca;Crosta, Andrea;Ghisotti, Daniela
通讯作者：
Ghisotti, Daniela
影响因子：
11.3
作者：
Gago G;Diacovich L;Arabolaza A;Tsai SC;Gramajo H
通讯作者：
Gramajo H
影响因子：
4.8
作者：
Diacovich, L;Peirú, S;Gramajo, H
通讯作者：
Gramajo, H
影响因子：
64.8
作者：
Cole, ST;Brosch, R;Barrell, BG
通讯作者：
Barrell, BG