Literature summary for 1.18.6.1 extracted from

Sarma, R.; Barney, B.; Keable, S.; Dean, D.; Seefeldt, L.; Peters, J.
Insights into substrate binding at FeMo-cofactor in nitrogenase from the structure of an alpha70Ile MoFe protein variant (2010), J. Inorg. Biochem., 104, 385-389.

Crystallization (Commentary)

Crystallization (Comment)	Organism
nitrogenase containing alpha70Ile mutant MoFe protein, 38 mg/ml protein is diluted in 50 mM Tris buffer, pH 8.0, and 250 mM NaCl, crystallization in 30% PEG 4000, 100 mM Tris, pH 8.0, 170-190 mM sodium molybdate, and 1 mM dithionite, 3-4 weeks, X-ray diffraction structure determination and analysis at 2.3 A resolution, comparison to the wild-type, with alpha70Val crystal structure, PDB ID 1M1N, overview	Azotobacter vinelandii

Crystallization (Comment)

Organism

nitrogenase containing alpha70Ile mutant MoFe protein, 38 mg/ml protein is diluted in 50 mM Tris buffer, pH 8.0, and 250 mM NaCl, crystallization in 30% PEG 4000, 100 mM Tris, pH 8.0, 170-190 mM sodium molybdate, and 1 mM dithionite, 3-4 weeks, X-ray diffraction structure determination and analysis at 2.3 A resolution, comparison to the wild-type, with alpha70Val crystal structure, PDB ID 1M1N, overview

Azotobacter vinelandii

Protein Variants

Protein Variants	Comment	Organism
V70I	substitution of alpha70Val by alpha70Ile results in a MoFe protein that is hampered in its ability to reduce a range of substrates including acetylene and N2, yet retains normal proton reduction activity. The mutant shows H2 evolution of greater than 2200 nmol/min/mg MoFe protein, which is 95% of the wild-type specific activity	Azotobacter vinelandii

Metals/Ions

Metals/Ions	Comment	Organism	Structure
Iron	in FeMo cofactor and MoFe protein	Azotobacter vinelandii
Molybdenum	in FeMo cofactor and MoFe protein	Azotobacter vinelandii

Organism

Organism	UniProt	Comment	Textmining
Azotobacter vinelandii	P07328	-	-

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg]	Specific Activity Maximum [µmol/min/mg]	Comment	Organism
2.2	-	about, micromol/min/mg MoFe protein, mutant enzyme, pH not specified in the publication, temperature not specified in the publication	Azotobacter vinelandii
2.316	-	about, micromol/min/mg MoFe protein, wild-type enzyme, pH not specified in the publication, temperature not specified in the publication	Azotobacter vinelandii

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.	Reac.
additional information	substrates bind and are reduced at a single 4Fe-4S face of the FeMo-cofactor. When alpha70Val is substituted by alpha70Ile, access of substrates to Fe6 of this face is effectively blocked	Azotobacter vinelandii	?	-	?

Cofactor

Cofactor	Comment	Organism	Structure
iron-molybdenum cofactor	modelling of the FeMo-cofactor binding site in the alpha70Ile MoFe protein structure	Azotobacter vinelandii

General Information

General Information	Comment	Organism
additional information	structure of the alpha70Ile MoFe protein compared to the alpha70Val wild-type MoFe protein, shows a delta-methyl group of alpha70Val that is positioned over Fe6 within the active site FeMo-cofactor	Azotobacter vinelandii