[reaction: see text]. Known lanosterol synthase mutants produce monocyclic or tetracyclic byproducts from oxidosqualene. We describe Erg7 Tyr510 mutants that cause partial substrate misfolding and generate a tricyclic byproduct. This novel triterpene, (13alphaH)-isomalabarica-14(27),17E,21-trien-3beta-ol, is the likely biosynthetic precursor of isomalabaricane triterpenoids in sponges. The results
[反应:请参见文字]。已知的
羊毛甾醇合酶突变体由氧化
角鲨烯产生单环或四环副产物。我们描述了Erg7 Tyr510突变体,该突变体导致部分底物错折叠并产生
三环副产物。这种新的三萜,(13alphaH)-异马巴拉基卡14(27),17E,21-
三烯-3beta-ol,是海绵中异马巴拉基烷三萜的可能的
生物合成前体。结果表明无柄动物中保护性三
萜类化合物的容易进化。