Molecular identification of the urea uptake system and transcriptional analysis of urea transporter- and urease-encoding genes in Corynebacterium glutamicum
Molecular identification of the urea uptake system and transcriptional analysis of urea transporter- and urease-encoding genes in Corynebacterium glutamicum
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DOI：
10.1128/jb.186.22.7645-7652.2004
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发表时间：
2004-11-01
影响因子：
3.2
通讯作者：
Burkovski, A
中科院分区：
文献类型：
--
作者：
Beckers, G;Bendt, AK;Burkovski, A
描述了谷氨酸棒杆菌尿素吸收系统的分子鉴定。这种ABC类型的转运蛋白由urtABCDE操纵子编码，该操纵子对氮素限制做出反应而转录。Urt基因的表达受全局氮调节因子amtR的调控，而amtR缺失菌株显示urtABCDE基因的结构性表达。AmtR抑制蛋白还控制谷氨酸杆菌中编码尿素酶的ureABCEFGD基因的转录。Ure基因簇形成一个操纵子，该操纵子主要是在氮饥饿时转录的。为了证实氮素限制条件下尿素酶亚基合成的增加，对氮素过剩和氮素限制条件下生长的细胞胞质蛋白提取物进行了蛋白质组学分析，鉴定了7个尿素酶亚基中的5个。
The molecular identification of the Corynebacterium glutamicum urea uptake system is described. This ABC-type transporter is encoded by the urtABCDE operon, which is transcribed in response to nitrogen limitation. Expression of the urt genes is regulated by the global nitrogen regulator AmtR, and an amtR deletion strain showed constitutive expression of the urtABCDE genes. The AmtR repressor protein also controls transcription of the urease-encoding ureABCEFGD genes in C. glutamicum. The ure gene cluster forms an operon which is mainly transcribed in response to nitrogen starvation. To confirm the increased synthesis of urease subunits under nitrogen limitation, proteome analyses of cytoplasmic protein extracts from cells grown under nitrogen surplus and nitrogen limitation were carried out, and five of the seven urease subunits were identified.