Vanadium nitrogenase - anomalous maps for resting and turnover states

The data set contains anomalous difference electron density maps (in CCP4 format) for two published crystal structures of Azotobacter vinelandii vanadium-dependent nitrogenase. These are:

1. VFe protein - resting state. PDB-ID 5N6Y.    Sippel et al. (2017) Nature Chem. Biol. 13, 956-960. DOI: 10.1038/Nchembio.2428

2. VFe protein - turnover state. PDB-ID 6FEA.  Sippel et al. (2018) Science 359, 1484-1489. DOI: 10.1126/science.aar2765

For each deposition, the maps provided are calculated with anomalous differences as Fourier coefficients, to 1.9 Å or 2.0 Å resoution, respectively. Depending on energies of data collection, these maps were used to visualize:

12398 eV - anomalous contirbution of iron ions

7000 eV - anomalous contribution of sulfur atoms (with strong contribution of V)

6200 eV - improved signal for S/Fe and S/V, respectively (not shown in publications).