Sugimoto H, Suzuki M, Nakagawa A, Tanaka I, Nishihira J
Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan.
FEBS Lett. 1996 Jul 1;389(2):145-8. doi: 10.1016/0014-5793(96)00553-4.
The three-dimensional structure of the macrophage migration inhibitory factor (MIF) from human lymphocytes has been determined by X-ray crystallography at 2.1 A resolution. The structure was solved by a molecular replacement technique using the coordinates of rat MIF. The molecule forms a trimer structure similar to the rat MIF. However, unlike the rat MIF whose C-terminal tail (residues 104-114) is disordered in the crystal, human MIF has a definite main-chain conformation up to the C-terminal end. These eleven residues create two more beta-strands and join to the inter-subunit beta-sheet, which contribute to forming a trimer structure. Thus, the trimer structure consists of three seven-stranded beta-sheets surrounded by six alpha-helices. Each beta-sheet is comprised of beta-strands from each of the three monomers. This architecture is almost identical to 5-carboxymethyl-2-hydroxymuconate isomerase (CHMI) and is related to the E. coli signal transducing protein PII.
通过X射线晶体学技术，已在2.1埃分辨率下测定了来自人淋巴细胞的巨噬细胞迁移抑制因子（MIF）的三维结构。该结构是利用大鼠MIF的坐标通过分子置换技术解析出来的。该分子形成了与大鼠MIF相似的三聚体结构。然而，与大鼠MIF不同，大鼠MIF的C末端尾巴（第104 - 114位残基）在晶体中无序，而人MIF直至C末端都有明确的主链构象。这11个残基形成了另外两条β链，并连接到亚基间的β折叠上，这有助于形成三聚体结构。因此，三聚体结构由三个七股β折叠组成，周围环绕着六个α螺旋。每个β折叠由来自三个单体各自的β链组成。这种结构与5 - 羧甲基 - 2 - 羟基粘康酸异构酶（CHMI）几乎相同，并且与大肠杆菌信号转导蛋白PII相关。
