Ohta T, Honda K, Kuroda M, Saito K, Hayashi H
Department of Microbiology, University of Tsukuba, Ibaraki, Japan.
Biochem Biophys Res Commun. 1993 Jun 15;193(2):730-7. doi: 10.1006/bbrc.1993.1686.
Methicillin-resistance of S.aureus (MRSA) was diminished or depressed at 44 degrees C. In order to investigate whether bacterial heat shock response is correlated with methicillin resistance, we examined the inducibility of the heat shock proteins (HSPs) in MRSA, and cloned and sequenced of their genes. A temperature shift from 37 degrees C to 46 degrees C enhanced the production of at least 8 kinds of cytoplasmic proteins as measured with two-dimensional PAGE. The induced protein profile was almost the same as methicillin sensitive S.aureus, and stress conditions due to ethanol, cadmium or low pH. Two of these proteins were HSP60 and HSP10. Their N-terminal amino acid sequences were 79%, and 83%, homologous with thermobacterium PS3, respectively. A positively hybridized 4.2 kbp DNA fragment encoding both proteins was isolated from the chromosomal DNA of MRSA. The resulting sequence revealed two reading frames and showed high homology to those of hsp60 (groEL) and hsp10 (groES) of bacteria (E.coli) and several other species. The genes of HSP60 and HSP10 in S.aureus comprised an operon as in E.coli. The relationship between those HSPs and PBP2' is currently under investigation.
金黄色葡萄球菌（MRSA）的耐甲氧西林能力在44摄氏度时会减弱或受到抑制。为了研究细菌热休克反应是否与耐甲氧西林能力相关，我们检测了MRSA中热休克蛋白（HSPs）的可诱导性，并对其基因进行了克隆和测序。从37摄氏度到46摄氏度的温度变化，通过二维聚丙烯酰胺凝胶电泳检测发现至少有8种细胞质蛋白的产生增加。诱导后的蛋白质图谱与甲氧西林敏感的金黄色葡萄球菌以及乙醇、镉或低pH值等应激条件下的图谱几乎相同。其中两种蛋白是HSP60和HSP10。它们的N端氨基酸序列分别与嗜热栖热菌PS3有79%和83%的同源性。从MRSA的染色体DNA中分离出一个正向杂交的4.2 kbp DNA片段，该片段编码这两种蛋白。所得序列显示有两个阅读框，并且与细菌（大肠杆菌）和其他几个物种的hsp60（groEL）和hsp10（groES）具有高度同源性。金黄色葡萄球菌中HSP60和HSP10的基因如大肠杆菌一样组成一个操纵子。目前正在研究这些HSPs与PBP2'之间的关系。
