Nakamura K, Nishiguchi M, Honda K, Yamane K
Institute of Biological Sciences, University of Tsukuba, Ibaraki, Japan.
Biochem Biophys Res Commun. 1994 Mar 30;199(3):1394-9. doi: 10.1006/bbrc.1994.1385.
B. subtilis Ffh is a homologue of SRP54, which is one component of the mammalian signal recognition particle. B. subtilis Ffh was expressed in E. coli as a derivative with a hexa histidine tag at the COOH terminus and purified to near homogeneity. The purified Ffh had intrinsic GTPase activity as predicted from its amino acid sequence. Using antiserum against Ffh, we also demonstrated that B. subtilis Ffh forms a complex with scRNA which is a B subtilis homologue of the RNA component of SRP in vivo, and that half of the resulting complex is found in the peripheral fraction of the cytoplasmic membrane where the initiation of protein translocation occurs. These findings provide evidence of a ribonucleoprotein complex in B. subtilis, reminiscent of SRP.
枯草芽孢杆菌Ffh是SRP54的同源物，SRP54是哺乳动物信号识别颗粒的一个组成部分。枯草芽孢杆菌Ffh在大肠杆菌中作为一种在COOH末端带有六组氨酸标签的衍生物进行表达，并纯化至接近均一性。纯化后的Ffh具有如从其氨基酸序列预测的内在GTP酶活性。使用针对Ffh的抗血清，我们还证明枯草芽孢杆菌Ffh与scRNA形成复合物，scRNA是体内SRP的RNA组分的枯草芽孢杆菌同源物，并且所形成复合物的一半存在于发生蛋白质转运起始的细胞质膜外周部分。这些发现提供了枯草芽孢杆菌中一种核糖核蛋白复合物的证据，让人联想到信号识别颗粒。
