Centre for Molecular and Structural Biochemistry, School of Biological Sciences and School of Chemistry, University of East Anglia, Norwich NR4 7TJ, United Kingdom.
Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA.
FEBS Lett. 2014 May 21;588(10):1886-90. doi: 10.1016/j.febslet.2014.04.013. Epub 2014 Apr 18.
The X-ray crystal structure of Shewanella oneidensis OmcA, an extracellular decaheme cytochrome involved in mineral reduction, was solved to a resolution of 2.7 Å. The four OmcA molecules in the asymmetric unit are arranged so the minimum distance between heme 5 on adjacent OmcA monomers is 9 Å, indicative of a transient OmcA dimer capable of intermolecular electron transfer. A previously identified hematite binding motif was identified near heme 10, forming a hydroxylated surface that would bring a heme 10 electron egress site to ∼10 Å of a mineral surface.
希瓦氏菌属脱细胞十联体细胞色素 OmcA 的 X 射线晶体结构已解析至 2.7Å 的分辨率，该结构涉及矿物还原。在不对称单元中排列有四个 OmcA 分子，使得相邻 OmcA 单体上的 5 号血红素之间的最小距离为 9Å，这表明存在瞬态 OmcA 二聚体，能够进行分子间电子转移。在 10 号血红素附近鉴定出了一个先前确定的赤铁矿结合基序，形成了一个羟基化表面，将血红素 10 的电子出口位点带到距矿物表面约 10Å 的位置。
