Catalysis-dependent selenium incorporation and migration in the nitrogenase active site iron-molybdenum cofactor
- Howard Hughes Medical Institute, California Institute of Technology, United States
- California Institute of Technology, United States
- University of Minnesota, United States
Figures
Figure 1 with 3 supplements
Selective Se-incorporation into the active site of the MoFe-protein.
(A) Side view of FeMoSe-cofactor ([7Fe:8S:1Se:Mo:C]-R-homocitrate) in Av1-Se2B at a resolution of 1.60 Å, highlighting the S2B replacement by Se. (B) View along the Fe1-C-Mo axis. The electron …
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Figure 1—source data 1
Numerical data for the graphs depicted in Figure 1D and 1E.
- https://doi.org/10.7554/eLife.11620.004
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Figure 1—source data 2
Numerical data for the graphs depicted in Figure 1—figure supplement 1.
- https://doi.org/10.7554/eLife.11620.005
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Figure 1—source data 3
Numerical data for the graphs depicted in Figure 1—figure supplement 2.
- https://doi.org/10.7554/eLife.11620.006
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Figure 1—source data 4
Numerical data for the graphs depicted in Figure 1—figure supplement 3.
- https://doi.org/10.7554/eLife.11620.007
Figure 1—figure supplement 1
CH4 production based on KSeCN and KSCN as substrates.
Methane production was determined based on 0.05, 0.1, 0.2, 0.5, 1, 2, 5 mM KSCN (red) or KSeCN (black) as substrates. Maximum CH4 production from KSeCN was obtained at a concentration of 1 mM, …
Figure 1—figure supplement 2
Inhibition of acetylene reduction by KSeCN and KSCN.
Inhibitory properties of KSeCN and KSCN were determined using a modified acetylene reduction assay. Concentrations for substrate (C2H2) were below saturation and concentrations for inhibitors (KSCN, …
Figure 1—figure supplement 3
Influence of KSeCN and KSCN on proton reduction.
Proton reduction activity as a function of KSeCN (black) or KSCN (red) concentrations (0, 0.5, 1, 5, 10 mM). H2 production in the presence of 10 mM KSeCN is approximately 65% when compared to 10 mM …
Figure 2
Se-migration in the active site during substrate reduction.
Se incorporation into all belt-S positions based on Av1-Se2B (FeMoSe-cofactor). (A) Se-occupancy in the active site as a function of numbers of acetylene reduced per cofactor. Se-occupancy of site …
Figure 3
Se-migration upon CO-binding to Av1-Se2B.
Structure of Av1-Se-CO at a resolution of 1.53 Å, highlighting the Se2B replacement by CO and migration of Se to the remaining belt-S sites. (A) View along the Fe1-C-Mo axis of the metal center. The …
Additional files
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Supplementary file 1
(A) Quantification of selenium occupancies at FeMoSe-cofactor belt x2B, x5A and x3A positions. (B) Data collection and refinement statistics.
- https://doi.org/10.7554/eLife.11620.013
