Keon J P, James C S, Court S, Baden-Daintree C, Bailey A M, Burden R S, Bard M, Hargreaves J A
Department of Agricultural Sciences, University of Bristol, Long Ashton Research Station, UK.
Curr Genet. 1994 Jun;25(6):531-7. doi: 10.1007/BF00351674.
The Magnaporthe grisea ERG2 gene, encoding delta 8-->delta 7 sterol isomerase, was isolated from a genomic library by heterologous hybridization to a fragment of the Ustilago maydis ERG2 gene. The isolated gene contained a reading frame of 745 bp which encoded a protein of 221 amino acids. The coding region was interrupted by a single putative 79-bp-long intron. The deduced amino-acid sequence exhibited similarity to the ERG2 gene products of U. maydis and of Saccharomyces cerevisiae, particularly in the central region of the proteins. The NH2-terminal of all three proteins contained a long stretch of amino acids that were strongly hydrophobic, suggesting that they may function by anchoring the protein to a membrane surface. The M. grisea ERG2 gene complemented a U. maydis deletion mutant in which the ERG2 gene had been removed using a one-step gene replacement procedure. The delta 8-->delta 7 sterol isomerase produced by the M. grisea ERG2 gene exhibited a level of sensitivity to the sterol biosynthesis inhibitor, tridemorph, similar to that of the enzyme derived from the U. maydis ERG2 gene.
通过与玉米黑粉菌ERG2基因片段进行异源杂交，从基因组文库中分离出稻瘟病菌编码δ8→δ7甾醇异构酶的ERG2基因。分离出的基因含有一个745 bp的阅读框，编码一个221个氨基酸的蛋白质。编码区被一个推定的79 bp长的内含子中断。推导的氨基酸序列与玉米黑粉菌和酿酒酵母的ERG2基因产物相似，特别是在蛋白质的中央区域。这三种蛋白质的NH2末端都含有一段很长的强疏水性氨基酸序列，表明它们可能通过将蛋白质锚定在膜表面发挥作用。稻瘟病菌ERG2基因补充了一个玉米黑粉菌缺失突变体，在该突变体中，ERG2基因已通过一步基因置换程序被去除。稻瘟病菌ERG2基因产生的δ8→δ7甾醇异构酶对甾醇生物合成抑制剂十三吗啉的敏感程度与来自玉米黑粉菌ERG2基因的酶相似。
