Brooke J S, Valvano M A
Department of Microbiology and Immunology, University of Western Ontario, London, Canada.
J Bacteriol. 1996 Jun;178(11):3339-41. doi: 10.1128/jb.178.11.3339-3341.1996.
We have determined that gene HI#1181 of Haemophilus influenzae is a homolog of Escherichia coli gmhA (previously designated lpcA) (J. S. Brooke and M. A. Valvano, J. Biol. Chem. 271:3608-3614, 1996), which encodes a phosphoheptose isomerase catalyzing the first step of the biosynthesis of ADP-L-glycero-D-manno heptose. Mutations in this gene are associated with a heptoseless core lipopolysaccharide which determines an increased outer membrane permeability to hydrophobic compounds. The cloned H. influenzae gmhA restored the synthesis of a complete core in the gmhA-deleted E. coli strain chi711. Amino acid sequence comparisons of the GmhA proteins of E. coli and H. influenzae with other proteins in the databases revealed the existence of a novel family of phosphosugar a1do-keto isomerases.
我们已经确定，流感嗜血杆菌的基因HI#1181是大肠杆菌gmhA（先前命名为lpcA）的同源物（J. S. 布鲁克和M. A. 瓦尔瓦诺，《生物化学杂志》271:3608 - 3614，1996），该基因编码一种磷酸庚糖异构酶，催化ADP - L - 甘油 - D - 甘露庚糖生物合成的第一步。该基因中的突变与无庚糖核心脂多糖相关，这种脂多糖会导致外膜对疏水性化合物的通透性增加。克隆的流感嗜血杆菌gmhA在gmhA缺失的大肠杆菌菌株chi711中恢复了完整核心的合成。将大肠杆菌和流感嗜血杆菌的GmhA蛋白与数据库中的其他蛋白进行氨基酸序列比较，揭示了一个新的磷酸糖醛糖 - 酮异构酶家族的存在。
