Differentiation-inducing factor 1 (DIF-1) is a polyketide-derived morphogen which drives stalk cell formation in the developmental cycle of
Dictyostelium discoideum
. Previous experiments demonstrated that the biosynthetic pathway proceeds via dichlorination of the precursor molecule THPH, but the enzyme responsible for this transformation has eluded characterization. Our recent studies on prokaryotic flavin-dependent halogenases and insights from the sequenced
Dd
genome led us to a candidate gene for this transformation. In this work, we present in vivo and in vitro evidence that
chlA
from
Dd
encodes a flavin-dependent halogenase capable of catalyzing both chlorinations in the biosynthesis of DIF-1. The results provide in vitro characterization of a eukaryotic oxygen-dependent halogenase and demonstrate a broad reach in biology for this molecular tailoring strategy, notably its involvement in the differentiation program of a social amoeba.
诱导分化因子1(DIF-1)是一种由聚酮衍生的形态因子,在
Dictyostelium discoideum的发育周期中促进茎细胞形成。先前的实验表明,
生物合成途径通过对前体分子THPH的二
氯化进行。但负责这一转化的酶尚未被表征。我们最近对原核
黄酮依赖卤素酶的研究以及从已测序的
Dd基因组中获得的见解,让我们找到了这一转化的候选
基因。在这项工作中,我们提供了体内和体外证据,表明
Dd中的
chlA编码一种能够催化DIF-1
生物合成中的两次
氯化的
黄酮依赖卤素酶。这些结果提供了一个关于真核氧依赖卤素酶的体外特征化,并展示了这种分子修饰策略在
生物学中的广泛应用,尤其是在社会变形虫的分化程序中的参与。