Characterization of a methyl-accepting chemotaxis protein gene, dmcA, from the oral spirochete Treponema denticola.
Characterization of a methyl-accepting chemotaxis protein gene, dmcA, from the oral spirochete Treponema denticola.
复制标题
来自口腔螺旋体齿垢密螺旋体的甲基接受趋化蛋白基因 dmcA 的表征。
DOI：
10.1128/iai.65.10.4011-4016.1997
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发表时间：
1997
影响因子：
3.1
通讯作者：
Kuramitsu,H
中科院分区：
文献类型：
--
作者：
Kataoka,M;Li,H;Arakawa,S;Kuramitsu,H
口腔螺旋体齿垢密螺旋体表达甲基接受趋化蛋白 (MCP) 的基因 dmcA 已得到表征。该基因最初被鉴定为紧接先前鉴定的 ATCC 35405 菌株 prtB 蛋白酶基因上游的开放阅读框。dmcA 基因的核苷酸测序揭示了一种潜在的 57-kDa 蛋白质产物，与多种细菌的 MCP 信号区域具有广泛的同源性。大肠杆菌中表达的蛋白质与抗Trg（大肠杆菌MCP）血清发生交叉反应，证实了其与MCP的同源性。 Northern 印迹和引物延伸分析鉴定了单顺反子 dmcA mRNA 的转录起始位点。利用本实验室最新开发的T. denticola基因灭活系统，构建了dmcA基因缺陷突变体HL0501。该突变体被证明对营养物质的趋化性有缺陷。此外，细胞蛋白的甲基化谱表明突变体中的 MCP 相对于亲本菌株发生了改变。这些结果表明我们已经在口腔螺旋体中鉴定出MCP基因，该基因在生物体的趋化反应中发挥重要作用。
A gene, dmcA, expressing a methyl-accepting chemotaxis protein (MCP) from the oral spirochete Treponema denticola has been characterized. The gene was initially identified as an open reading frame immediately upstream from the previously characterized prtB protease gene of strain ATCC 35405. Nucleotide sequencing of the dmcA gene revealed a potential 57-kDa protein product with extensive homology with the signaling regions of MCPs from a variety of bacteria. The protein expressed in Escherichia coli cross-reacted with anti-Trg (E. coli MCP) serum, confirming its homology with MCPs. Northern blot and primer extension analyses identified the transcription start site of the monocistronic dmcA mRNA. By utilizing a T. denticola gene inactivation system recently developed in this laboratory, a mutant defective in the dmcA gene, HL0501, was constructed. The mutant was demonstrated to be defective in chemotaxis toward nutrients. In addition, the methylation profiles of cellular proteins indicated altered MCPs in the mutant relative to those of the parental strain. These results indicate that we have identified an MCP gene in the oral spirochete which plays a significant role in the chemotactic response of the organism.