Sayavedra-Soto L A, Arp D J
Laboratory for Nitrogen Fixation Research, Oregon State University, Corvallis 97331-2902.
J Bacteriol. 1992 Aug;174(16):5295-301. doi: 10.1128/jb.174.16.5295-5301.1992.
The roles of the product of the hoxZ gene immediately downstream of the hydrogenase gene (hoxKG) in Azotobacter vinelandii were investigated by constructing and characterizing a mutant with the center of the hoxZ gene deleted. The strain lacking the functional hoxZ gene product exhibited a low rate of H2 oxidation with O2 as the electron acceptor relative to that of the wild-type strain. Nevertheless, when the enzyme was exogenously activated and methylene blue was used as the electron acceptor from hydrogenase, rates of H2 oxidation comparable to those in the wild-type strain were observed. These results suggest that the gene product of hoxZ plays a role in activating and maintaining hydrogenase in a reduced active state. The product of hoxZ could also be the linkage necessary for transfer of electrons from H2 to the electron transport chain.
通过构建并鉴定一个缺失hoxZ基因中心区域的突变体，研究了维涅兰德固氮菌中氢化酶基因（hoxKG）下游紧邻的hoxZ基因产物的作用。相对于野生型菌株，缺乏功能性hoxZ基因产物的菌株以O2作为电子受体时，H2氧化速率较低。然而，当该酶被外源激活且使用亚甲基蓝作为氢化酶的电子受体时，观察到H2氧化速率与野生型菌株相当。这些结果表明，hoxZ基因产物在激活并维持氢化酶处于还原活性状态中发挥作用。hoxZ基因产物也可能是H2向电子传递链传递电子所需的连接物。
