Yabuta Yukinori, Kamei Yukiko, Bito Tomohiro, Arima Jiro, Yoneda Kazunari, Sakuraba Haruhiko, Ohshima Toshihisa, Nakano Yoshihisa, Watanabe Fumio
a Faculty of Agriculture, School of Agricultural, Biological, and Environmental Sciences , Tottori University , Tottori , Japan.
Biosci Biotechnol Biochem. 2015;79(5):710-7. doi: 10.1080/09168451.2014.993353. Epub 2014 Dec 17.
Methylmalonyl-CoA mutase (MCM) requires 5'-deoxyadenosylcobalamin (AdoCbl) as a cofactor and is widely distributed in organisms from bacteria and animals. Although genes encoding putative MCMs are present in many archaea, they are separately encoded in large and small subunits. The large and small subunits of archaeal MCM are similar to the catalytic and AdoCbl-binding domains of human MCM, respectively. In Pyrococcus horikoshii OT3, putative genes PH1306 and PH0275 encode the large and small subunits, respectively. Because information on archaeal MCM is extremely restricted, we examined the functional and structural characteristics of P. horikoshii MCM. Reconstitution experiments using recombinant PH0275 and PH1306 showed that these proteins assemble in equimolar ratios and form of heterotetrameric complexes in the presence of AdoCbl. Subsequent immunoprecipitation experiments using anti-PH0275 and anti-PH1306 antibodies suggested that PH0275 and PH1306 form a complex in P. horikoshii cells in the presence of AdoCbl.
甲基丙二酰辅酶A变位酶（MCM）需要5'-脱氧腺苷钴胺素（AdoCbl）作为辅因子，广泛分布于细菌和动物等生物体中。尽管许多古菌中存在编码假定MCM的基因，但它们分别编码为大亚基和小亚基。古菌MCM的大亚基和小亚基分别与人MCM的催化结构域和AdoCbl结合结构域相似。在嗜热栖热菌OT3中，假定基因PH1306和PH0275分别编码大亚基和小亚基。由于关于古菌MCM的信息极为有限，我们研究了嗜热栖热菌MCM的功能和结构特征。使用重组PH0275和PH1306进行的重组实验表明，这些蛋白质以等摩尔比组装，并在AdoCbl存在下形成异源四聚体复合物。随后使用抗PH0275和抗PH1306抗体进行的免疫沉淀实验表明，在AdoCbl存在下，PH0275和PH1306在嗜热栖热菌细胞中形成复合物。
