CRYSTAL-STRUCTURE OF HEMOPROTEIN DOMAIN OF P450BM-3, A PROTOTYPE FOR MICROSOMAL P450S
CRYSTAL-STRUCTURE OF HEMOPROTEIN DOMAIN OF P450BM-3, A PROTOTYPE FOR MICROSOMAL P450S
复制标题
DOI：
10.1126/science.8342039
复制
发表时间：
1993-08-06
期刊：
影响因子：
56.9
通讯作者：
DEISENHOFER, J
中科院分区：
文献类型：
--
作者：
RAVICHANDRAN, KG;BODDUPALLI, SS;DEISENHOFER, J
细胞色素P450 BM-3是一种细菌脂肪酸单加氧酶，在一级结构和功能上类似于真核微粒体P450及其黄素蛋白还原酶。P450 BM-3血红素蛋白结构域的三维结构通过X射线衍射测定，并在2.0埃分辨率下精确到16.9%的R因子。该结构由α和β结构域组成。活性位点血红素可通过主要由β结构域和α结构域的B'和F螺旋形成的长疏水通道进入。不对称单元中的两个分子在底物结合口袋周围的构象不同。P450 BM-3和P450 cam之间的实质性差异，唯一的其他P450结构可用，观察周围的基板结合口袋和区域的氧化还原伴侣结合的重要。还提出了P450中质子转移的一般机制。
Cytochrome P450BM-3, a bacterial fatty acid monooxygenase, resembles the eukaryotic microsomal P450's and their flavoprotein reductase in primary structure and function. The three-dimensional structure of the hemoprotein domain of P450BM-3 was determined by x-ray diffraction and refined to an R factor of 16.9 percent at 2.0 angstrom resolution. The structure consists of an alpha and a beta domain. The active site heme is accessible through a long hydrophobic channel formed primarily by the beta domain and the B' and F helices of the alpha domain. The two molecules in the asymmetric unit differ in conformation around the substrate binding pocket. Substantial differences between P450BM-3 and P450cam, the only other P450 structure available, are observed around the substrate binding pocket and the regions important for redox partner binding. A general mechanism for proton transfer in P450's is also proposed.