Williams S G, Attridge S R, Manning P A
Department of Microbiology and Immunology, University of Adelaide, South Australia.
Mol Microbiol. 1993 Aug;9(4):751-60. doi: 10.1111/j.1365-2958.1993.tb01735.x.
HlyU upregulates expression of the haemolysin, HlyA, of Vibrio cholerae. DNA sequence analysis indicates that HlyU is an 11.9 kDa protein containing a putative helix-turn-helix motif and belonging to a family of small regulatory proteins, including NoIR (Rhizobium meliloti), SmtB (Synechococcus PCC 7942) and ArsR (plasmids R773, Escherichia coli; pI258, Staphylococcus aureus; and pSX267, Staphylococcus xylosus). An hlyU mutant was constructed by insertional inactivation, and found to be deficient in the production of both the haemolysin and a 28 kDa secreted protein. The mutant was assessed for virulence in the infant mouse cholera model, revealing a 100-fold increase in the LD50. This suggests that HlyU promotes expression of virulence determinant(s) in vivo.
HlyU上调霍乱弧菌溶血素HlyA的表达。DNA序列分析表明，HlyU是一种11.9 kDa的蛋白质，含有一个假定的螺旋-转角-螺旋基序，属于一类小调节蛋白家族，包括NoIR（苜蓿根瘤菌）、SmtB（聚球藻PCC 7942）和ArsR（质粒R773，大肠杆菌；pI258，金黄色葡萄球菌；以及pSX267，木糖葡萄球菌）。通过插入失活构建了hlyU突变体，发现其溶血素和一种28 kDa分泌蛋白的产生均有缺陷。在幼鼠霍乱模型中评估了该突变体的毒力，结果显示其半数致死剂量（LD50）增加了100倍。这表明HlyU在体内促进毒力决定因素的表达。
