Fink-Lavi Eyal, Eichler Jerry
FEMS Microbiol Lett. 2008 Jan;278(2):257-60. doi: 10.1111/j.1574-6968.2007.01000.x. Epub 2007 Dec 6.
Sec11b is one of two signal peptidases (SPases) in the haloarchaeon Haloferax volcanii. Site-directed mutagenesis revealed Ser-72, His-137 and Asp-187 as essential for signal peptide cleavage. Thus, like the SPase of the methanoarchaeon Methanococcus voltae, H. volcanii Sec11b uses a catalytic mechanism reminiscent of its eukaryal rather than its bacterial counterpart. The availability of an additional model system to study the archaeal SPase, now in the form of the purified protein, promises additional insight into the behavior of this enzyme.
Sec11b是嗜盐古菌沃氏嗜盐碱杆菌中的两种信号肽酶（SPases）之一。定点诱变显示，Ser-72、His-137和Asp-187对于信号肽切割至关重要。因此，与甲烷古菌沃氏甲烷球菌的信号肽酶一样，沃氏嗜盐碱杆菌Sec11b使用的催化机制类似于其真核生物对应物，而非细菌对应物。现在有了以纯化蛋白形式存在的用于研究古菌信号肽酶的额外模型系统，有望对这种酶的行为有更多了解。
