Protein dynamics and the all-ferrous [Fe4 S4 ] cluster in the nitrogenase iron protein.

ABSTRACT: In nitrogen fixation by Azotobacter vinelandii nitrogenase, the iron protein (FeP) binds to and subsequently transfers electrons to the molybdenum-FeP, which contains the nitrogen fixation site, along with hydrolysis of two ATPs. However, the nature of the reduced state cluster is not completely clear. While reduced FeP is generally thought to contain an [Fe4 S4 ](1+) cluster, evidence also exists for an all-ferrous [Fe4 S4 ](0) cluster. Since the former indicates a single electron is transferred per two ATPs hydrolyzed while the latter indicates two electrons could be transferred per two ATPs hydrolyzed, an all-ferrous [Fe4 S4 ](0) cluster in FeP is potenially two times more efficient. However, the 1+/0 reduction potential has been measured in the protein at both 460 and 790 mV, causing t

SUBMITTER: Tan ML 

PROVIDER: S-EPMC4815322 | biostudies-literature | 2016 Jan

REPOSITORIES: biostudies-literature