Bacik John-Paul, Mekasha Sophanit, Forsberg Zarah, Kovalevsky Andrey Y, Vaaje-Kolstad Gustav, Eijsink Vincent G H, Nix Jay C, Coates Leighton, Cuneo Matthew J, Unkefer Clifford J, Chen Julian C-H
Protein Crystallography Station, Bioscience Division, Los Alamos National Laboratory , Los Alamos, New Mexico 87545, United States.
Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU) , PO Box 5003, 1430 Ås, Norway.
Biochemistry. 2017 May 23;56(20):2529-2532. doi: 10.1021/acs.biochem.7b00019. Epub 2017 May 11.
A 1.1 Å resolution, room-temperature X-ray structure and a 2.1 Å resolution neutron structure of a chitin-degrading lytic polysaccharide monooxygenase domain from the bacterium Jonesia denitrificans (JdLPMO10A) show a putative dioxygen species equatorially bound to the active site copper. Both structures show an elongated density for the dioxygen, most consistent with a Cu(II)-bound peroxide. The coordination environment is consistent with Cu(II). In the neutron and X-ray structures, difference maps reveal the N-terminal amino group, involved in copper coordination, is present as a mixed ND and ND, suggesting a role for the copper ion in shifting the pK of the amino terminus.
来自反硝化琼斯氏菌（JdLPMO10A）的几丁质降解溶菌多糖单加氧酶结构域在1.1 Å分辨率的室温X射线结构和2.1 Å分辨率的中子结构中，显示出一种假定的双氧物种赤道向结合于活性位点铜。两种结构均显示出双氧的拉长密度，最符合与Cu（II）结合的过氧化物。配位环境与Cu（II）一致。在中子和X射线结构中，差值图显示参与铜配位的N端氨基以混合的ND和ND形式存在，表明铜离子在改变氨基末端的pK中起作用。
