Yokoyama Hideshi, Matsui Ikuo
School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
FEBS Open Bio. 2014 Sep 16;4:804-12. doi: 10.1016/j.fob.2014.09.002. eCollection 2014.
Stomatin, prohibitin, flotillin, and HflK/C (SPFH) domain proteins are found in the lipid raft microdomains of various cellular membranes. Stomatin/STOPP (stomatin operon partner protein) gene pairs are present in both archaeal and bacterial species, and their protein products may be involved in the quality control of membrane proteins. In the present study, the crystal structure of the C-terminal soluble domain of STOPP PH1510 (1510-C) from the hyperthermophilic archaeon Pyrococcus horikoshii was determined at 2.4 Å resolution. The structure of 1510-C had a compact five-stranded β-barrel fold known as an oligosaccharide/oligonucleotide-binding fold (OB-fold). According to crystal packing, 1510-C could assemble into multimers based on a dimer as a basic unit. 1510-C also formed a large cylinder-like structure composed of 24 subunits or a large triangular prism-like structure composed of 12 subunits. These results indicate that 1510-C functions as a scaffold protein to form the multimeric assembly of STOPP and stomatin.
气孔蛋白、抑制素、浮舰蛋白和HflK/C（SPFH）结构域蛋白存在于各种细胞膜的脂筏微区中。气孔蛋白/STOPP（气孔蛋白操纵子伴侣蛋白）基因对存在于古细菌和细菌物种中，它们的蛋白质产物可能参与膜蛋白的质量控制。在本研究中，嗜热古菌火之神 Pyrococcus horikoshii 的 STOPP PH1510（1510-C）C 端可溶性结构域的晶体结构在 2.4 Å 分辨率下被确定。1510-C 的结构具有紧凑的五链β桶折叠，称为寡糖/寡核苷酸结合折叠（OB 折叠）。根据晶体堆积，1510-C 可以以二聚体为基本单元组装成多聚体。1510-C 还形成了由 24 个亚基组成的大圆柱状结构或由 12 个亚基组成的大三角棱柱状结构。这些结果表明，1510-C 作为一种支架蛋白，形成 STOPP 和气孔蛋白的多聚体组装。
