A new GntR family transcriptional regulator in Streptomyces coelicolor is required for morphogenesis and antibiotic production and controls transcription of an ABC transporter in response to carbon source
A new GntR family transcriptional regulator in Streptomyces coelicolor is required for morphogenesis and antibiotic production and controls transcription of an ABC transporter in response to carbon source
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DOI：
10.1128/jb.00898-06
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发表时间：
2006-11-01
影响因子：
3.2
通讯作者：
Westpheling, Janet
中科院分区：
文献类型：
--
作者：
Hillerich, Brandan;Westpheling, Janet
我们最近报道了一种转座子产生的突变的分离和初步鉴定，该突变导致了colicolor链霉菌的形态发生和抗生素产生缺陷。插入确定SCO7168开放阅读框，其预测产物是GntR家族转录调控因子。在这里，我们发现这个基因可以抑制自身的转录，以及在S. coelicolor染色体上紧邻它的一系列基因的转录，这些基因可能编码一个atp结合盒（ABC）型转运体，用于碳水化合物的摄取。这种转运体的转录被生长在相对较差的碳源（如海藻糖和二糖）上强烈诱导，被乳糖和甘油（而不是葡萄糖）弱诱导，并且诱导不被葡萄糖的存在所抑制。ABC转运蛋白自身的构建缺失导致了原始转座子突变的抑制，这表明ABC转运蛋白的不适当表达至少在一定程度上导致了突变表型。由于这种转运体对a-糖苷的存在有反应，并且与这类其他两种碳水化合物转运体相似，我们将转运体的基因命名为agl3E、agl3F和agl3G，并根据既定的命名法将调节转运体agl3R转录的gntr样蛋白命名为agl3R。我们认为，agl3R是链霉菌中众多同源蛋白之一（在S. coelicolor基因组中有57个推测的GntR家族调节因子），这些同源蛋白响应营养和/或环境信号，控制影响形态发生和抗生素产生的基因。
We recently reported the isolation and initial characterization of a transposon-generated mutation that resulted in defects in both morphogenesis and antibiotic production in Streptomyces coelicolor. The insertion identified the SCO7168 open reading frame whose predicted product is a GntR family transcriptional regulator. Here, we show that this gene acts to repress transcription of itself as well as a series of genes immediately adjacent to it on the S. coelicolor chromosome that likely encode an ATP-binding cassette (ABC)-type transporter for carbohydrate uptake. Transcription of this transporter is strongly induced by growth on relatively poor carbon sources such as trehalose and melibiose and weakly induced by lactose and glycerol but not glucose, and induction is not repressed by the presence of glucose. Constructed deletions of the ABC transporter itself resulted in the suppression of the original transposon mutation, suggesting that inappropriate expression of the ABC transporter is responsible, at least in part, for the mutant phenotype. Because this transporter responds to the presence of a-glucosides and has similarity to two other carbohydrate transporters of this class, we have named the genes of the transporter agl3E, agl3F, and agl3G and the GntR-like protein that regulates transcription of the transporter agl3R in accordance with established nomenclature. We suggest that agl3R is one of a number of homologous proteins in Streptomyces (there are 57 putative GntR family regulators in the S. coelicolor genome) that respond to nutritional and/or environmental signals to control genes that affect morphogenesis and antibiotic production.