Guillén-Navarro Karina, Encarnación Sergio, Dunn Michael F
Programa de Ingeniería Metabólica, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, A.P. 565-A, Cuernavaca, Morelos, Mexico.
FEMS Microbiol Lett. 2005 May 15;246(2):159-65. doi: 10.1016/j.femsle.2005.04.020.
Biotin, a B-group vitamin, performs an essential metabolic function in all organisms. Rhizobia are alpha-proteobacteria with the remarkable ability to form a nitrogen-fixing symbiosis in combination with a compatible legume host, a process in which the importance of biotin biosynthesis and/or transport has been demonstrated for some rhizobia-legume combinations. Rhizobia have also been used to delimit the biosynthesis, metabolic effects and, more recently, transport of biotin. Molecular genetic analysis shows that an orthodox biotin biosynthesis pathway occurs in some rhizobia while others appear to synthesize the vitamin using alternative pathways. In addition to its well established function as a prosthetic group for biotin-dependent carboxylases, we are beginning to delineate a role for biotin as a metabolic regulator in rhizobia.
生物素是一种B族维生素，在所有生物中发挥着重要的代谢功能。根瘤菌是α-变形菌，具有与相容豆科植物宿主形成固氮共生关系的显著能力，在某些根瘤菌-豆科植物组合中，已证明生物素生物合成和/或转运在这一过程中具有重要性。根瘤菌也被用于确定生物素的生物合成、代谢作用以及最近的转运情况。分子遗传学分析表明，一些根瘤菌中存在传统的生物素生物合成途径，而另一些根瘤菌似乎使用替代途径合成这种维生素。除了作为生物素依赖性羧化酶辅基的既定功能外，我们开始描绘生物素在根瘤菌中作为代谢调节因子的作用。
