Bouma C L, Roseman S
Department of Biology and the McCollum-Pratt Institute, The Johns Hopkins University, Baltimore, Maryland 21218, USA.
J Biol Chem. 1996 Dec 27;271(52):33457-67. doi: 10.1074/jbc.271.52.33457.
Chitin catabolism by the marine bacterium Vibrio furnissii involves chemotaxis to and transport of N-acetyl-D-glucosamine (GlcNAc) and D-glucose. We report the properties of the respective permeases that complemented E. coli Glc- Man- mutants. Although the V. furnissii Glc-specific permease (55,941 Da) shares 38% identity with E. coli IIGlc (ptsG), it is 67% identical to MalX of the E. coli maltose operon (Reidl, J., and Boos, W. (1991) J. Bacteriol. 173, 4862-4876). An adjacent open reading frame encodes a protein with 52% identity to E. coli MalY. Glc phosphorylation requires only V. furnissii MalX and the accessory phosphoenolpyruvate:glycose phosphotransferase system proteins. The V. furnissii equivalent of IIGlc was not found in the 25,000 transformants screened. The GlcNAc/Glc-specific permease (52,894 Da) shares 47% identity with the N-terminal, hydrophobic domain of E. coli IINag, but is unique among IINag proteins in that it lacks the C-terminal domain and thus requires IIIGlc for sugar fermentation in vivo and phosphorylation in vitro. While there are similarities between the phosphoenolpyruvate:glycose phosphotransferase system of V. furnissii and enteric bacteria, the differences may be important for survival of V. furnissii in the marine environment.
弗氏弧菌对几丁质的分解代谢涉及对N - 乙酰 - D - 葡萄糖胺（GlcNAc）和D - 葡萄糖的趋化作用及转运。我们报道了互补大肠杆菌Glc - Man - 突变体的相应通透酶的特性。尽管弗氏弧菌的葡萄糖特异性通透酶（55,941道尔顿）与大肠杆菌IIGlc（ptsG）有38%的同一性，但它与大肠杆菌麦芽糖操纵子的MalX有67%的同一性（赖德尔，J.，和布斯，W.（1991年）《细菌学杂志》173，4862 - 4876）。一个相邻的开放阅读框编码一种与大肠杆菌MalY有52%同一性的蛋白质。葡萄糖磷酸化仅需要弗氏弧菌的MalX和辅助的磷酸烯醇丙酮酸：葡萄糖磷酸转移酶系统蛋白。在筛选的25,000个转化体中未发现弗氏弧菌中与IIGlc等效的蛋白。GlcNAc/Glc特异性通透酶（52,894道尔顿）与大肠杆菌IINag的N端疏水结构域有47%的同一性，但在IINag蛋白中是独特的，因为它缺乏C端结构域，因此在体内糖发酵和体外磷酸化过程中需要IIIGlc。虽然弗氏弧菌的磷酸烯醇丙酮酸：葡萄糖磷酸转移酶系统与肠道细菌之间存在相似性，但这些差异可能对弗氏弧菌在海洋环境中的生存很重要。
