Biogenesis of a putative channel protein, ComEC, required for DNA uptake: membrane topology, oligomerization and formation of disulphide bonds

被引:118
作者
Draskovic, I [1 ]
Dubnau, D [1 ]
机构
[1] Int Ctr Publ Hlth, Publ Hlth Res Inst, Newark, NJ 07103 USA
关键词
D O I
10.1111/j.1365-2958.2004.04430.x
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
ComEC is a putative channel protein for DNA uptake in Bacillus subtilis and other genetically transformable bacteria. Membrane topology studies suggest a model of ComEC as a multispanning membrane protein with seven transmembrane segments (TMSs), and possibly with one laterally inserted amphipathic helix. We show that ComEC contains an intramolecular disulphide bond in its N-terminal extracellular loop (between the residues C131 and C172), which is required for the stability of the protein, and is probably introduced by BdbDC, a pair of competence-induced oxidoreductase proteins. By in vitro cross-linking using native cysteine residues we show that ComEC forms an oligomer. The oligomerization surface includes a transmembrane segment, TMS-G, near the cytoplasmic C-terminus of ComEC.
引用
收藏
页码:881 / 896
页数:16
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