Chemistry & Biochemistry

Permanent URI for this communityhttps://scholarworks.montana.edu/handle/1/42

The Department of Chemistry and Biochemistry offers research-oriented programs culminating in the Doctor of Philosophy degree. The faculty in the department have expertise over a broad range of specialty areas including synthesis, structure, spectroscopy, and mechanism. In each of these fields, the strength of the department has been recognized at the international level.

Browse

Filters

20171

Settings

Author: search.filters.author.Peters, John W.search.filters.applied.f.department: search.filters.department.Chemical & Biological Engineering.

Search Results

Now showing 1 - 1 of 1
  • Thumbnail Image
    Item
    Unraveling the interactions of the physiological reductant flavodoxin with the different conformations of the Fe protein in the nitrogenase cycle
    (2017-08) Pence, Natasha; Tokmina-Lukaszewska, Monika; Yang, Zhi-Yong; Ledbetter, Rhesa N.; Seefeldt, Lance C.; Bothner, Brian; Peters, John W.
    Nitrogenase reduces dinitrogen (N2) to ammonia in biological nitrogen fixation. The nitrogenase Fe protein cycle involves a transient association between the reduced, MgATP-bound Fe protein and the MoFe protein and includes electron transfer, ATP hydrolysis, release of Pi , and dissociation of the oxidized, MgADP-bound Fe protein from the MoFe protein. The cycle is completed by reduction of oxidized Fe protein and nucleotide exchange. Recently, a kinetic study of the nitrogenase Fe protein cycle involving the physiological reductant flavodoxin reported a major revision of the rate-limiting step from MoFe protein and Fe protein dissociation, to release of Pi . Since the Fe protein cannot interact with flavodoxin and the MoFe protein simultaneously, knowledge of the interactions between flavodoxin and the different nucleotide states of the Fe protein is critically important for understanding the Fe protein cycle. Here, we used time-resolved limited proteolysis and chemical cross-linking to examine nucleotide-induced structural changes in the Fe protein and their effects on interactions with flavodoxin. Differences in proteolytic cleavage patterns and chemical cross-linking patterns were consistent with known nucleotide-induced structural differences in the Fe protein and indicated that MgATP-bound Fe protein resembles the structure of the Fe protein in the stabilized nitrogenase complex structures. Docking models and cross-linking patterns between the Fe protein and flavodoxin revealed that the MgADP-bound state of the Fe protein has the most complementary docking interface with flavodoxin compared with the MgATP-bound state. Together, these findings provide new insights into the control mechanisms in protein-protein interactions during the Fe protein cycle.
Copyright (c) 2002-2022, LYRASIS. All rights reserved.