Mellado E, Aufauvre-Brown A, Gow N A, Holden D W
Department of Infectious Diseases and Bacteriology, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.
Mol Microbiol. 1996 May;20(3):667-79. doi: 10.1046/j.1365-2958.1996.5571084.x.
Two genes, designated chsC and chsG were isolated from DNA libraries of the opportunistic fungal pathogen, Aspergillus fumigatus. The genes were characterized with respect to their nucleotide sequences and mutant phenotypes. The complete deduced amino acid sequences of chsC and chsG show that the products of both genes are Class III zymogen-type enzymes. A mutant strain constructed by disruption of chsC is phenotypically indistinguishable from the wild-type strain, but chsG- and chsC- chsG- strains have reduced colony radial growth rate and chitin synthase activity, conidiate poorly and produce highly branched hyphae. Despite these defects, the double-mutant strain retained the ability to cause pulmonary disease in neutropenic mice. However, in comparison to the wild-type strain, there was a decrease in mortality and delay in the onset of illness in mice inoculated with the double-mutant strain, which was associated with smaller and more highly branched fungal colonies in lung tissue.
从机会性真菌病原体烟曲霉的DNA文库中分离出两个基因，分别命名为chsC和chsG。对这些基因的核苷酸序列和突变体表型进行了表征。chsC和chsG完整推导的氨基酸序列表明，这两个基因的产物都是III类酶原型酶。通过破坏chsC构建的突变菌株在表型上与野生型菌株没有区别，但chsG -和chsC - chsG -菌株的菌落径向生长速率和几丁质合酶活性降低，分生孢子形成不良并产生高度分支的菌丝。尽管存在这些缺陷，双突变菌株仍保留了在中性粒细胞减少小鼠中引起肺部疾病的能力。然而，与野生型菌株相比，接种双突变菌株的小鼠死亡率降低且发病延迟，这与肺组织中较小且分支更多的真菌菌落有关。
