Regulatory mechanism of genes involved in chitin degradation system of bacteria

细菌几丁质降解系统相关基因的调控机制

基本信息

批准号：
16580066
负责人：
TSUJIBO Hiroshi
金额：
$ 2.18万
依托单位：
Osaka University of Pharmaceutical Sciences
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2004
资助国家：
日本
起止时间：
2004 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-16580066/
关键词：
marine bacteria actinomycete chitin chitin degradation chitinase gene regulation

项目摘要

We found that four chitinases (ChiA, ChiB, ChiC, and ChiD), three β-N-acetylglucosaminidases (GlcNAcases A, B, and C), a transglycosylative enzyme (Hex99), a chitin-binding protein (Cbp1), a serine protease (AprIV) and a metalloprotease (MprIII) were involved in chitin degradation system of Pseudoalteromonas sp. strain O-7. AprIV and chitinases were induced in the presence of N-acetylglucosamine (GlcNAc). These results suggest that AprIV and chitinases might be coordinately controlled by the same regulatory system. Recently, we have found that ArcA, which is a response regulator of ArcB/ArcA two-component signal transduction system, binds to the upstream region of aprIV gene. The arcA and arcB genes were cloned and expressed in Escherichia coli. The ArcA protein as a response regulator was transphosphorylated by the ArcB protein as a sensor kinase. The ArcA protein was also phosphorylated by acetylphosphate which is an indicator of nutritive conditions of cells. Transphosphorylation fr … More om ArcB to ArcA was promoted by GlcNAc which is a component of chitin. Generally ArcA-ArcB is a two-component signal transduction system which facilitates adaptation to anoxia. However, our research indicated that ArcA plays an important role even in aerated conditions. Gel retardation assay and BIAcore analysis demonstrated that phosphorylated ArcA (ArcA-P) more tightly bound to the upstream region of aprIV and chiD genes compared to those of chiA, chiB, chiC, and cpb1 genes. Furthermore, footprint analyses indicate that ArcA-P binds to the consensus sequence, 5'-ACAATTAGANNNNNACTAAAACA-3'. The consensus sequence was found near the promoter region of each gene. These results suggest that ArcB/ArcA two-component signal transduction system negatively regulates the expression of genes involved in chitin degradation system of the strain.On the other hand, Streptomyces thermoviolaceus OPC-520 produced four chitinases (Chi40, Chi35, Chi30, Chi25) in the presence of chitin. These genes contain a common similar pair of direct repeat sequences in the promoter regions, which have been suggested to be involved in both chitin induction and glucose repression. We found that regulatory gene involved in induction existed in the upstream region of genes encoding chitobiose transporter. We are doing the cloning and expression of the regulatory gene to examine whether the gene product binds to the direct repeat sequences of chitinase genes. Less

We found that four chitinases (ChiA, ChiB, ChiC, and ChiD), three β-N-acetylglucosamiidases (GlcNAcases A, B, and C), a transglycosylative enzyme (Hex99), a chitin-binding protein (Cbp1), a serine protein (AprIV) and a metalloprotease (MprIII) were involved in chitin伪后瘤的降解系统。菌株O-7。在存在N-乙酰葡萄糖（GLCNAC）的情况下诱导APRIV和几丁质酶。这些结果表明，APRIV和几丁质酶可能由同一调节系统协调控制。最近，我们发现ARCA是ARCB/ARCA两组信号转导系统的响应调节剂，它与APRIV基因上游区域结合。将ARCA和ARCB基因克隆并在大肠杆菌中表达。 ArcB蛋白作为传感器激酶将ARCA蛋白作为反应调节剂被磷酸化。 ARCA蛋白还通过乙酰磷酸磷酸化，这是细胞营养条件的指标。 GlcNAC促进了磷酸化的Fr…更多的OM ARCB，这是几丁质的组成部分。通常，ARCA-ARCB是一种两组分组转导系统，该系统设施适应缺氧。但是，我们的研究表明，即使在充气条件下，ARCA也起着重要作用。与CHIA，CHIB，CHIB，CHIC和CPB1基因相比，凝胶延迟测定法和BIACORE分析表明，磷酸化的ARCA（ARCA-P）更紧密地与APRIV和CHID基因的上游区域结合。此外，足迹分析表明，ARCA-P与共有序列（5'-acaattagantagannnnnnnnnntacaaaaca-3'结合）。共识序列在每个基因的启动子区域附近发现。这些结果表明，ARCB/ARCA两组分组信号转导系统对菌株的几丁质降解系统的基因表达。另一方面，Therpomyces therpomyces opc-520产生了四个几丁丁蛋白（CHI40，CHI35，CHI35，CHI30，CHI3，CHI25，CHI25）。这些基因在启动子区域中包含一个常见的类似的直接重复序列，这些序列已被认为参与了几丁质诱导和葡萄糖表达。我们发现，编码壳聚糖转运蛋白的基因上游区域中存在参与诱导的调节基因。我们正在进行调节基因的克隆和表达，以检查基因产物是否与几丁质酶基因的直接重复序列结合。较少的