Complex metabolic phenotypes caused by a mutation in yjgF, encoding a member of the highly conserved YER057c/YjgF family of proteins
Complex metabolic phenotypes caused by a mutation in yjgF, encoding a member of the highly conserved YER057c/YjgF family of proteins
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DOI：
10.1128/jb.180.24.6519-6528.1998
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发表时间：
1998-12-01
影响因子：
3.2
通讯作者：
Downs, DM
中科院分区：
文献类型：
--
作者：
Enos-Berlage, JL;Langendorf, MJ;Downs, DM
氧化戊糖磷酸途径是替代嘧啶生物合成途径的功能所必需的，在鼠伤寒沙门氏菌中，该途径允许在缺乏PurF酶的情况下合成硫胺素。已分离出不再需要氧化戊糖磷酸途径合成硫胺素功能的突变体。对这些突变体的进一步表型分析表明，它们对培养基中丝氨酸的存在也很敏感，这表明异亮氨酸生物合成存在部分缺陷。遗传鉴定表明，这些多向表型是由yjgF的零突变引起的，yjgF是一个先前未被表征的开放阅读框，编码一个假设的13.5 kda蛋白。YjgF蛋白属于一类功能未知的蛋白质，在从细菌到人类的广泛生物中表现出惊人的保守性。这项工作代表了任何生物体中yjgF突变体的第一个详细表型特征，并为这类高度保守的蛋白质的功能提供了重要线索。结果还表明异亮氨酸生物合成途径的功能与硫胺素合成中戊糖磷酸途径的需求之间存在联系。
The oxidative pentose phosphate pathway is required for function of the alternative pyrimidine biosynthetic pathway, a pathway that allows thiamine synthesis in the absence of the PurF enzyme in Salmonella typhimurium. Mutants that no longer required function of the oxidative pentose phosphate pathway for thiamine synthesis were isolated. Further phenotypic analyses of these mutants demonstrated that they were also sensitive to the presence of serine in the medium, suggesting a partial defect in isoleucine biosynthesis. Genetic characterization showed that these pleiotropic phenotypes were caused by null mutations in yjgF, a previously uncharacterized open reading frame encoding a hypothetical 13.5-kDa protein. The YjgF protein belongs to a class of proteins of unknown function that exhibit striking conservation across a wide range of organisms, from bacteria to humans. This work represents the first detailed phenotypic characterization of yjgF mutants in any organism and provides important clues as to the function of this highly conserved class of proteins. Results also suggest a connection between function of the isoleucine biosynthetic pathway and the requirement for the pentose phosphate pathway in thiamine synthesis.