Lütticke Christiane, Hauske Patrick, Lewandrowski Urs, Sickmann Albert, Kaiser Markus, Ehrmann Michael
Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany.
Mol Biosyst. 2012 Jun;8(6):1775-82. doi: 10.1039/c2mb05506f. Epub 2012 Apr 11.
YggG is a conserved lipoprotein localized to the outer membrane of Gram negative bacteria. Even though the expressed open reading frame has been identified previously, the Escherichia coli protein remained uncharacterized. We report that YggG of E. coli is a metalloprotease that cleaves its targets preferentially between Phe-Phe residues. Since the yggG promoter is upregulated when bacteria are subjected to media of low osmolarity, YggG was named LoiP (low osmolarity induced protease). LoiP has an intramolecular disulfide (S-S) bond that is formed even in the absence of the periplasmic oxido-reductase DsbA and proper membrane localization of LoiP can depend on another putative metalloprotease, YfgC.
YggG是一种保守的脂蛋白，定位于革兰氏阴性菌的外膜。尽管之前已鉴定出其表达的开放阅读框，但大肠杆菌中的该蛋白仍未得到充分表征。我们报告称，大肠杆菌的YggG是一种金属蛋白酶，它优先在苯丙氨酸-苯丙氨酸残基之间切割其靶标。由于当细菌处于低渗透压培养基中时yggG启动子会上调，因此YggG被命名为LoiP（低渗透压诱导蛋白酶）。LoiP具有分子内二硫键（S-S），即使在没有周质氧化还原酶DsbA的情况下也会形成，并且LoiP的正确膜定位可能依赖于另一种假定的金属蛋白酶YfgC。
