The<i>Fusarium solani</i>Gene Encoding Kievitone Hydratase, a Secreted Enzyme that Catalyzes Detoxification of a Bean Phytoalexin
作者:Daoxin Li
DOI:10.1094/mpmi-8-0388
日期:——
vulgaris (French bean) is the prenylated isoflavonoid, kievitone. The bean pathogen, Fusarium solani f. sp. phaseoli, secretes a glycoenzyme, kievitone hydratase (EC 4.2.1.95), which catalyzes conversion of kievitone to a less toxic metabolite. Among F. solani strains, those that are highly virulent to P. vulgaris also produce kievitone hydratase constitutively, suggesting that the enzyme is a virulence
菜豆(French bean)产生的抗菌素植物抗毒素中有异戊烯基异黄酮,酮基酮。蚕豆病原菌Fusarium solani f。sp。菜豆油会分泌一种糖酵素,基维酮水合酶(EC 4.2.1.95),可催化基维酮转化为毒性较小的代谢物。在茄形镰刀菌菌株中,对寻常型毕赤酵母具有高毒性的菌株也组成型地产生酮维酮水合酶,表明该酶是一种毒力因子。基于纯化的酶的N末端氨基酸序列,克隆了酮酸水合酶cDNA和基因(khs)。khs和cDNA的同一性通过它们在转基因Neurospora crassa和Emericella nidulans中的表达得以证实。根据基因和cDNA序列,预计khs可编码350个氨基酸的前蛋白,在成熟和分泌过程中从中除去19个氨基酸的N末端转运肽。成熟多肽的预测质量为37 kDa,与纯化酶的电泳估计的47至49 kDa大小相反,这证实了该酶被广泛糖基化。推断的多肽序列具有七个用于N-糖基化的规范位点。F