Jones Heather A, Lillard James W, Perry Robert D
Microbiology (Reading). 1999 Aug;145 ( Pt 8):2117-2128. doi: 10.1099/13500872-145-8-2117.
The haemin storage (Hms) phenotype of Yersinia pestis has been shown to be involved in the blockage of fleas that is required for the transmission of plague from fleas to mammals. Previously, an operon encoding four genes, hmsHFRS, that are essential for the temperature-regulated Hms+ phenotype has been characterized. Here the isolation and characterization of a fifth gene, hmsT, that is essential for this phenotype is described. Conceptual translation of hmsT suggests it encodes a 44.8 kDa protein with a pl of 7.75. The gene for HmsT is located outside of the approximately 102 kb pgm locus of Y. pestis that contains the hmsHFRS operon. Hybridization studies indicate that Yersinia pseudotuberculosis but not Yersinia enterocolitica or Escherichia coli possesses a highly homologous gene. HmsT belongs to a family of PleD-related proteins with four highly conserved regions of homology. Although PleD is a regulator, the functions of the other members of this family have not been experimentally determined. The iron-responsive regulator, Fur, has previously been implicated in temperature regulation of the Hms phenotype. A good potential Fur-binding site (FBS) is located upstream of hmsT. Y. pestis M23 and two of five Y. pseudotuberculosis strains, which all exhibit a temperature-constitutive Hms phenotype, contain a 6 bp insertion in the putative FBS. E. coli MG1655 contains homologues of hmsHFRST (ycdSRQPT) but has an Hms- phenotype. Only ycdQ and ycdP complement mutations in their respective homologues, hmsR and hmsS, in Y. pestis.
鼠疫耶尔森菌的血红素储存（Hms）表型已被证明与跳蚤堵塞有关，而跳蚤堵塞是鼠疫从跳蚤传播到哺乳动物所必需的。此前，已鉴定出一个编码四个基因hmsHFRS的操纵子，该操纵子对于温度调节的Hms +表型至关重要。本文描述了该表型所必需的第五个基因hmsT的分离和鉴定。hmsT的概念性翻译表明它编码一种44.8 kDa的蛋白质，其等电点为7.75。HmsT基因位于鼠疫耶尔森菌约102 kb的pgm基因座之外，该基因座包含hmsHFRS操纵子。杂交研究表明，假结核耶尔森菌拥有一个高度同源的基因，而小肠结肠炎耶尔森菌或大肠杆菌则没有。HmsT属于PleD相关蛋白家族，具有四个高度保守的同源区域。尽管PleD是一种调节因子，但该家族其他成员的功能尚未通过实验确定。铁响应调节因子Fur先前已被证明与Hms表型的温度调节有关。一个良好的潜在Fur结合位点（FBS）位于hmsT上游。鼠疫耶尔森菌M23和五株假结核耶尔森菌中的两株均表现出温度组成型Hms表型，它们在假定的FBS中含有一个6 bp的插入。大肠杆菌MG1655含有hmsHFRST（ycdSRQPT）的同源物，但具有Hms -表型。只有ycdQ和ycdP能够互补鼠疫耶尔森菌中其各自同源物hmsR和hmsS中的突变。
