Kawata Y, Doi K, Omoto H, Mizobata T, Nagai J
Department of Biotechnology, Faculty of Engineering, Tottori University, Japan.
Cell Stress Chaperones. 1998 Sep;3(3):200-7. doi: 10.1379/1466-1268(1998)003<0200:pacoca>2.3.co;2.
Two proteins belonging to the group I chaperonin family were isolated from an obligate methanotroph, Methylobacillus glycogenes. The two proteins, one a GroEL homologue (cpn60: M. glycogenes 60 kDa chaperonin) and the other a GroES homologue (cpn10: M. glycogenes 10 kDa chaperonin), composed a heteropolymeric complex in the presence of ATP. Both proteins were purified from crude extracts of M. glycogenes by anion-exchange (DEAE-Toyopearl) and gel-filtration (Sephacryl S-400) chromatography. The native molecular weights of each chaperonin protein as determined by high-performance liquid chromatography (HPLC) gel-filtration were 820 000 for cpn60 and 65 000 for cpn10. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the subunit molecular weights of cpn60 and cpn10 were 58 000 and 10 000, respectively. Both cpn60 and cpn10 possessed amino acid sequences which were highly homologous to other group I chaperonins. M. glycogenes cpn60 displayed an ATPase activity which was inhibited in the presence of cpn10. The chaperonins also displayed an ability to interact with and facilitate the refolding of Thermus malate dehydrogenase and yeast enolase in a manner similar to that of GroEL/ES. The similarities between the Escherichia coli GroE proteins are discussed.
从专性甲烷氧化菌甘氨酸甲基杆菌中分离出了两种属于第一类伴侣蛋白家族的蛋白质。这两种蛋白质，一种是GroEL同源物（cpn60：甘氨酸甲基杆菌60 kDa伴侣蛋白），另一种是GroES同源物（cpn10：甘氨酸甲基杆菌10 kDa伴侣蛋白），在ATP存在的情况下组成了一个异聚复合体。两种蛋白质均通过阴离子交换（DEAE-琼脂糖凝胶）和凝胶过滤（Sephacryl S-400）色谱法从甘氨酸甲基杆菌的粗提物中纯化得到。通过高效液相色谱（HPLC）凝胶过滤测定的每种伴侣蛋白的天然分子量，cpn60为820 000，cpn10为65 000。十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示，cpn60和cpn10的亚基分子量分别为58 000和10 000。cpn60和cpn10都具有与其他第一类伴侣蛋白高度同源的氨基酸序列。甘氨酸甲基杆菌cpn60表现出ATP酶活性，在cpn10存在时受到抑制。这些伴侣蛋白还表现出与苹果酸热硫化叶菌脱氢酶和酵母烯醇化酶相互作用并促进其重折叠的能力，其方式与GroEL/ES类似。文中讨论了大肠杆菌GroE蛋白之间的相似性。
