Imperial College London

Professor Bill Rutherford FRS

Faculty of Natural SciencesDepartment of Life Sciences

Chair in Biochemistry of Solar Energy
 
 
 
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Contact

 

+44 (0)20 7594 5329a.rutherford Website

 
 
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Location

 

702Sir Ernst Chain BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Varghese:2019:10.1074/jbc.RA118.007285,
author = {Varghese, F and Kabasakal, BV and Cotton, CA and Schumacher, J and Rutherford, AW and Fantuzzi, A and Murray, JW},
doi = {10.1074/jbc.RA118.007285},
journal = {Journal of Biological Chemistry},
title = {A low-potential terminal oxidase associated with the iron-only nitrogenase from the nitrogen-fixing bacterium Azotobacter vinelandii},
url = {http://dx.doi.org/10.1074/jbc.RA118.007285},
year = {2019}
}

RIS format (EndNote, RefMan)

TY  - JOUR
AB - The biological route for nitrogen gas entering the biosphere is reduction to ammonia by the nitrogenase enzyme, which is inactivated by oxygen. Three types of nitrogenase exist, the least studied of which is the iron-only nitrogenase. The Anf3 protein in the bacterium Rhodobacter capsulatus is essential for diazotrophic (i.e. nitrogen-fixing) growth with the iron-only nitrogenase, but its enzymatic activity and function are unknown. Here, we biochemically and structurally characterize Anf3 from the model diazotrophic bacterium Azotobacter vinelandii. Determining the Anf3 crystal structure to atomic resolution, we observed that it is a dimeric flavocytochrome with an unusually close interaction between the heme and the flavin adenine dinucleotide cofactors. Measuring the reduction potentials by spectroelectrochemical redox titration, we observed values of -420 ± 10 mV and -330 ± 10 mV for the two FAD potentials and -340 ± 1 mV for the heme. We further show that Anf3 accepts electrons from spinach ferredoxin and that Anf3 consumes oxygen without generating superoxide or hydrogen peroxide. We predict that Anf3 protects the iron-only nitrogenase from oxygen inactivation by functioning as an oxidase in respiratory protection, with flavodoxin or ferredoxin as the physiological electron donors.
AU - Varghese,F
AU - Kabasakal,BV
AU - Cotton,CA
AU - Schumacher,J
AU - Rutherford,AW
AU - Fantuzzi,A
AU - Murray,JW
DO - 10.1074/jbc.RA118.007285
PY - 2019///
SN - 0021-9258
TI - A low-potential terminal oxidase associated with the iron-only nitrogenase from the nitrogen-fixing bacterium Azotobacter vinelandii
T2 - Journal of Biological Chemistry
UR - http://dx.doi.org/10.1074/jbc.RA118.007285
UR - https://www.ncbi.nlm.nih.gov/pubmed/31043481
UR - http://hdl.handle.net/10044/1/70417
ER -