McClain M S, Hurley M C, Brieland J K, Engleberg N C
Department of Microbiology, University of Michigan Medical School, Ann Arbor 48109-0620, USA.
Infect Immun. 1996 May;64(5):1532-40. doi: 10.1128/iai.64.5.1532-1540.1996.
We continued characterization of the Legionella pneumophila hel locus. Mutagenesis and DNA sequencing identified three genes similar to the czc and cnr loci of Alcaligenes eutrophus and the ncc locus of Alcaligenes xylosoxidans. On the basis of their similarity to these loci, we designated the L. pneumophila genes helC, helB, and helA. Mutations in the hel genes led to reduced cytopathicity towards U937 cells, although the mutant strains did not appear defective in other assays of virulence. Transcription of the hel locus was induced by the intracellular environment but was not induced by any of a variety of in vitro stress conditions. The function of the hel gene products remains to be determined.
我们继续对嗜肺军团菌hel位点进行特性分析。诱变和DNA测序鉴定出三个与产碱杆菌的czc和cnr位点以及木糖氧化产碱杆菌的ncc位点相似的基因。基于它们与这些位点的相似性，我们将嗜肺军团菌的这些基因命名为helC、helB和helA。hel基因的突变导致对U937细胞的细胞病变效应降低，尽管突变菌株在其他毒力测定中未表现出缺陷。hel位点的转录由细胞内环境诱导，但不受多种体外应激条件中的任何一种诱导。hel基因产物的功能仍有待确定。
