DIRECT REPEAT SEQUENCES ARE IMPLICATED IN THE REGULATION OF 2 STREPTOMYCES CHITINASE PROMOTERS THAT ARE SUBJECT TO CARBON CATABOLITE CONTROL
DIRECT REPEAT SEQUENCES ARE IMPLICATED IN THE REGULATION OF 2 STREPTOMYCES CHITINASE PROMOTERS THAT ARE SUBJECT TO CARBON CATABOLITE CONTROL
复制标题
DOI：
10.1073/pnas.89.5.1885
复制
发表时间：
1992-03-01
影响因子：
11.1
通讯作者：
WESTPHELING, J
中科院分区：
文献类型：
--
作者：
DELIC, I;ROBBINS, P;WESTPHELING, J
我们报道了两个几丁质酶基因启动子的鉴定和部分特性。几丁质酶是由链霉菌和其他土壤微生物产生的一种酶，用于消化土壤中丰富的碳和氮来源几丁质。两种几丁质酶的启动子区域是通过与xylE报告基因的转录融合来确定的。转录被证明是葡萄糖敏感和几丁质依赖的。每个启动子包含一个假定的RNA聚合酶结合位点，其识别序列与许多真细菌营养表达基因中观察到的序列非常相似。在这两个启动子中，一对12碱基对的直接重复序列重叠在假定的RNA聚合酶结合位点上。对其中一个启动子的进一步分析表明，直接重复序列中的单碱基变化导致体内葡萄糖抵抗，不依赖几丁质的表达。此外，包括直接重复序列的启动子区域在体外被证明与序列特异性DNA结合因子相互作用。类似的直接重复序列也存在于最近被发现的其他几丁质酶基因中，我们认为这些重复序列可能参与了这一类分解代谢控制基因的抑制和诱导。
We report the identification and partial characterization of the promoters for two chitinase genes from Streptomyces plicatus. Chitinases are a family of enzymes made by Streptomyces and other soil microbes to digest chitin, an abundant source of carbon and nitrogen in the soil. The promoter regions of two chitinases were defined by using transcriptional fusions to the xylE reporter gene. Transcription was shown to be glucose-sensitive and chitin-dependent. Each promoter contains a putative RNA polymerase binding site with a recognition sequence very similar to that observed in many eubacterial vegetatively expressed genes. In both promoters, a pair of 12-base-pair direct repeat sequences overlap the putative RNA polymerase binding sites. Further analysis of one of the promoters revealed that a single-base change within the direct repeat sequences resulted in glucose-resistant, chitin-independent expression in vivo. In addition, the promoter region that includes the direct repeat sequences was shown to interact with a sequence-specific DNA binding factor in vitro. Similar direct repeat sequences are present in other chitinase genes recently characterized, and we suggest that these repeats may be involved in repression and induction for this entire class of catabolite-controlled genes.