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1rw4
From Proteopedia
| |||||||
| , resolution 2.5Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , | ||||||
| Gene: | nifH (Azotobacter vinelandii) | ||||||
| Activity: | Nitrogenase, with EC number 1.18.6.1 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Nitrogenase Fe protein l127 deletion variant
Overview
The crystal structure of a nitrogenase Fe protein single site deletion variant reveals a distinctly new conformation of the Fe protein and indicates that, upon binding of MgATP, the Fe protein undergoes a dramatic conformational change that is largely manifested in the rigid-body reorientation of the homodimeric Fe protein subunits with respect to one another. The observed conformational state allows the rationalization of a model of structurally and chemically complementary interactions that occur upon initial complex formation with the MoFe protein component that are distinct from the protein-protein interactions that have been characterized previously for stabilized nitrogenase complexes. The crystallographic results, in combination with complementary UV-visible absorption, EPR, and resonance Raman spectroscopic data, indicate that the [4Fe-4S] cluster of both the Fe protein deletion variant and the native Fe protein in the presence of MgATP can reversibly cycle between a regular cubane-type [4Fe-4S] cluster in the reduced state and a cleaved form involving two [2Fe-2S] fragments in the oxidized state. Resonance Raman studies indicate that this novel cluster conversion is induced by glycerol, and the crystallographic data suggest that glycerol is bound as a bridging bidentate ligand to both [2Fe-2S] cluster fragments in the oxidized state.
About this Structure
1RW4 is a Single protein structure of sequence from Azotobacter vinelandii. Full crystallographic information is available from OCA.
Reference
A conformational mimic of the MgATP-bound "on state" of the nitrogenase iron protein., Sen S, Igarashi R, Smith A, Johnson MK, Seefeldt LC, Peters JW, Biochemistry. 2004 Feb 24;43(7):1787-97. PMID:14967020
Page seeded by OCA on Sun Mar 30 23:33:46 2008
