Uptake of N,N′-Diacetylchitobiose [(GlcNAc)2] via the Phosphotransferase System Is Essential for Chitinase Production by Serratia marcescens 2170
Uptake of N,N′-Diacetylchitobiose [(GlcNAc)2] via the Phosphotransferase System Is Essential for Chitinase Production by Serratia marcescens 2170
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通过磷酸转移酶系统摄取 N,N-二乙酰壳二糖 [(GlcNAc)2] 对于粘质沙雷氏菌 2170 生产几丁质酶至关重要
DOI：
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发表时间：
2003
影响因子：
3.2
通讯作者：
Takeshi Watanabe
中科院分区：
文献类型：
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作者：
T. Uchiyama;R. Kaneko;J. Yamaguchi;Akane Inoue;Takahiro Yanagida;N. Nikaidou;M. Regué;Takeshi Watanabe
摘要 粘质沙雷氏菌 2170 的 chiR 基因编码 LysR 型转录激活因子，之前被鉴定为几丁质酶和几丁质结合蛋白 CBP21 表达的必需因子。为了鉴定几丁质酶产生所必需的其他基因，用mini-Tn5Km1进行转座子诱变，获得了25个不能产生几丁质酶和CBP21的突变体。对其中一个突变体 N22 的突变基因进行分析，发现该细菌中存在 pts 操纵子，并且在操纵子的 ptsI 中发现了突变。除了无法产生几丁质酶外，N22 在 N-乙酰基-d-葡萄糖胺 (GlcNAc)、(GlcNAc)2 和其他一些碳源（其中大部分是磷酸转移酶系统 (PTS) 糖）上生长不佳。因此，考虑到(GlcNAc)2是几丁质酶诱导的最小底物以及该细菌的几丁质酶水解几丁质的主要产物，认为无法产生几丁质酶是由于通过PTS摄取(GlcNAc)2的缺陷引起的。为了证实这一假设，参考大肠杆菌对应物克隆了编码 (GlcNAc)2 特异性酶 II 通透酶的 chb 操纵子，并且沙雷氏菌 chb 操纵子被证明包含 chbB、chbC、bglA、chbR 和 chbG。 chbC 的破坏大大减少了几丁质酶和 CBP21 的产生，并损害了胶体几丁质的生长。这些结果表明 (GlcNAc)2 的摄取是由 PTS 介导的，并且 (GlcNAc)2 特异性酶 II 渗透酶构成了其主要途径。由于 (GlcNAc)2 摄取对于几丁质酶的诱导和 CBP21 的产生至关重要，因此 (GlcNAc)2 似乎是粘质链球菌识别和利用几丁质的关键分子。
ABSTRACT The chiR gene of Serratia marcescens 2170, encoding a LysR-type transcriptional activator, was identified previously as an essential factor for expression of chitinases and a chitin-binding protein, CBP21. To identify other genes that are essential for chitinase production, transposon mutagenesis with mini-Tn5Km1 was carried out, and 25 mutants that were unable to produce chitinases and CBP21 were obtained. Analysis of the mutated gene of one of the mutants, N22, revealed the presence of a pts operon in this bacterium, and a mutation was found in ptsI in the operon. In addition to its inability to produce chitinase, N22 did not grow well on N-acetyl-d-glucosamine (GlcNAc), (GlcNAc)2, and some other carbon sources, most of which were phosphotransferase system (PTS) sugars. Thus, the inability to produce chitinase was assumed to be caused by the defect in uptake of (GlcNAc)2 via the PTS, considering that (GlcNAc)2 is the minimal substrate for chitinase induction and the major product of chitin hydrolysis by chitinases of this bacterium. To confirm this assumption, the chb operon, encoding the (GlcNAc)2-specific enzyme II permease, was cloned by reference to its Escherichia coli counterpart, and the Serratia chb operon was shown to comprise chbB, chbC, bglA, chbR, and chbG. Disruption of chbC drastically reduced production of chitinases and CBP21 and impaired growth on colloidal chitin. These results indicate that uptake of (GlcNAc)2 is mediated by the PTS and that the (GlcNAc)2-specific enzyme II permease constitutes its major pathway. Since (GlcNAc)2 uptake is essential for induction of chitinases and CBP21 production, (GlcNAc)2 appears to be the key molecule in recognition and utilization of chitin by S. marcescens.
通过细菌磷酸转移酶系统进行糖转运。
DOI：
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发表时间：
1987
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Saffen,DW;Presper,KA;Doering,TL;Roseman,S
通讯作者：
Roseman,S