Santoro N, Konisky J
J Bacteriol. 1987 Feb;169(2):660-5. doi: 10.1128/jb.169.2.660-665.1987.
Mutants of Methanococcus voltae were isolated that were resistant to the coenzyme M (CoM; 2-mercaptoethanesulfonic acid) analog 2-bromoethanesulfonic acid (BES). The mutants displayed a reduced ability to accumulate [35S]BES relative to the sensitive parental strain. BES inhibited methane production from CH3-S-CoM in cell extracts prepared from wild-type sensitive or resistant strains. BES uptake required the presence of both CO2 and H2 and was inhibited by N-ethylmaleimide and several reagents that are known to disrupt energy metabolism. The mutants showed normal uptake of isoleucine and were not cross-resistant to either azaserine or 5-methyltryptophan and, thus, were neither defective in general energy-dependent substrate transport nor envelope permeability. Both HS-CoM and CH3-S-CoM prevented the uptake of BES and protected cells from inhibition by it. We propose that M. voltae has an energy-dependent, carrier-mediated uptake system for HS-CoM and CH3-S-CoM which can also mediate uptake of BES.
分离出了对辅酶M（CoM；2-巯基乙烷磺酸）类似物2-溴乙烷磺酸（BES）具有抗性的沃氏甲烷球菌突变体。相对于敏感的亲本菌株，这些突变体积累[35S]BES的能力降低。BES抑制了从野生型敏感或抗性菌株制备的细胞提取物中由CH3-S-CoM产生甲烷。BES的摄取需要CO2和H2同时存在，并受到N-乙基马来酰亚胺和几种已知会破坏能量代谢的试剂的抑制。这些突变体对异亮氨酸的摄取正常，对重氮丝氨酸或5-甲基色氨酸均无交叉抗性，因此，它们在一般的能量依赖性底物转运或包膜通透性方面均无缺陷。HS-CoM和CH3-S-CoM均能阻止BES的摄取，并保护细胞免受其抑制。我们提出，沃氏甲烷球菌具有一种能量依赖性的、载体介导的HS-CoM和CH3-S-CoM摄取系统，该系统也能介导BES的摄取。
