文章基本信息

标题：ApoNifH functions in iron–molybdenum cofactor synthesis and apodinitrogenase maturation
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作者：Priya Rangaraj ; Vinod K. Shah ; Paul W. Ludden 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1997
卷号：94
期号：21
页码：11250-11255
DOI：10.1073/pnas.94.21.11250
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：NifH (dinitrogenase reductase) has three important roles in the nitrogenase enzyme system. In addition to its role as the obligate electron donor to dinitrogenase, NifH is required for the iron-molybdenum cofactor (FeMo-co) synthesis and apodinitrogenase maturation. We have investigated the requirement of the Fe-S cluster of NifH for these processes by preparing apoNifH. The 4Fe-4S cluster of NifH was removed by chelation of the cluster with , '-bipyridyl. The resulting apoNifH was tested in in vitro FeMo-co synthesis and apodinitrogenase maturation reactions and was found to function in both these processes. Thus, the presence of a redox active 4Fe-4S cluster in NifH is not required for its function in FeMo-co synthesis and in apodinitrogenase maturation. This, in turn, implies that the role of NifH in these processes is not one of electron transfer or of iron or sulfur donation.
关键词：Azotobacter vinelandii ; nitrogenase ; dinitrogenase reductase ; nitrogen fixation ; molybdenum ; iron–sulfur cluster