Koomey M, Bergstrom S, Blake M, Swanson J
Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor 48109-0402.
Mol Microbiol. 1991 Feb;5(2):279-87. doi: 10.1111/j.1365-2958.1991.tb02108.x.
Spontaneous mutants of Neisseria gonorrheae failing to express pili or having diminished levels of piliation were studied with regard to pilin expression. All mutants displayed altered pilin processing detectable as the release of soluble, truncated pilin molecules (S-pilin). Of particular interest was the finding, in one mutant, that substitution of serine for glycine at position -1 of propilin, a highly conserved residue among N-metPhe and related pilins, abolished pilus expression but not S-pilin release. The degree of S-pilin processing and the levels of membrane-associated pilin varied among the different classes of mutants, suggesting that each was blocked at a distinct step of pilus biogenesis. The data support a model in which increased S-pilin processing is a result of a decreased rate of pilus polymerization.
对淋病奈瑟菌中未能表达菌毛或菌毛化水平降低的自发突变体进行了菌毛蛋白表达方面的研究。所有突变体均显示出菌毛蛋白加工过程发生改变，可检测到可溶性截短菌毛蛋白分子（S-菌毛蛋白）的释放。特别值得关注的是，在一个突变体中发现，在前菌毛蛋白-1位的甘氨酸被丝氨酸取代，前菌毛蛋白是N-metPhe及相关菌毛蛋白中高度保守的残基，这消除了菌毛表达，但并未阻止S-菌毛蛋白的释放。不同类别的突变体中S-菌毛蛋白的加工程度和膜相关菌毛蛋白的水平各不相同，这表明每个突变体在菌毛生物合成的不同步骤受阻。这些数据支持了一个模型，即S-菌毛蛋白加工增加是菌毛聚合速率降低的结果。
