Ishihara Kazuyuki, Kuramitsu Howard K, Okuda Katsuji
Department of Microbiology, Oral Health Science Center, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan.
FEMS Microbiol Lett. 2004 Mar 19;232(2):181-8. doi: 10.1016/S0378-1097(04)00067-9.
A protease of Treponema denticola, dentilisin, is thought to be part of a complex with 43- and 38-kDa proteins. A sequence encoding a 43-kDa protein was located in the 3' region of the prcA gene upstream of the dentilisin gene (prtP). The 43-kDa protein was apparently generated from digestion of PrcA. To clarify the function of the protein, we constructed a mutant of the 43-kDa protein following homologous recombination. The mutant lacked detectable dentilisin activity. Immunoblot analysis demonstrated that the dentilisin protein was degraded in the mutant. The results of real-time polymerase chain reaction suggested that prtP mRNA expression in the mutant was somewhat decreased compared with the wild-type strain. These data suggest that the 43-kDa protein is involved in the stabilization of the dentilisin protein.
齿垢密螺旋体的一种蛋白酶——牙本质素，被认为是与43 kDa和38 kDa蛋白质形成复合物的一部分。编码43 kDa蛋白质的序列位于牙本质素基因（prtP）上游的prcA基因的3'区域。43 kDa蛋白质显然是由PrcA消化产生的。为了阐明该蛋白质的功能，我们通过同源重组构建了43 kDa蛋白质的突变体。该突变体缺乏可检测到的牙本质素活性。免疫印迹分析表明，牙本质素蛋白在突变体中被降解。实时聚合酶链反应结果表明，与野生型菌株相比，突变体中prtP mRNA表达有所下降。这些数据表明，43 kDa蛋白质参与了牙本质素蛋白的稳定化。
