Florentin D, Bui B T, Marquet A, Ohshiro T, Izumi Y
Laboratoire de Chimie Organique Biologique, URA CNRS 493, Université Paris-VI, France.
C R Acad Sci III. 1994 Jun;317(6):485-8.
A cell-free system of a bioB transformant of Bacillus sphaericus, effecting the last step of biotin biosynthesis, namely the introduction of sulfur into dethiobiotin has been recently described. S-adenosyl methionine (SAM) is absolutely necessary for activity. We show here, through experiments with [35S]SAM and [35S]Cys, that the sulfur donor is not SAM but probably cysteine (Cys) or a derivative. This finding together with the fact that NADPH and FAD are required for activity leads us to postulate some analogy between the biotin synthase system and other systems which use SAM as a source of desoxyadenosyl radical.
最近报道了球形芽孢杆菌bioB转化体的无细胞系统，该系统实现生物素生物合成的最后一步，即将硫引入脱硫生物素。S-腺苷甲硫氨酸（SAM）对于活性是绝对必需的。我们通过用[35S]SAM和[35S]半胱氨酸（Cys）进行的实验表明，硫供体不是SAM，而可能是半胱氨酸（Cys）或其衍生物。这一发现以及活性需要NADPH和FAD这一事实，使我们推测生物素合酶系统与其他以SAM作为脱氧腺苷自由基来源的系统之间存在某些相似之处。
