A V-Nitrogenase Variant Containing a Citrate-Substituted Cofactor
Newcomb, MP; Lee, CC; Tanifuji, K; Jasniewski, AJ; Liedtke, J; Ribbe, MW; Hu, Y
| HERO ID | 6308320 |
|---|---|
| In Press | No |
| Year | 2019 |
| Title | A V-Nitrogenase Variant Containing a Citrate-Substituted Cofactor |
| Authors | Newcomb, MP; Lee, CC; Tanifuji, K; Jasniewski, AJ; Liedtke, J; Ribbe, MW; Hu, Y |
| Journal | ChemBiochem |
| Volume | 21 |
| Issue | 12 |
| Page Numbers | 1742-1748 |
| Abstract | Nitrogenases catalyze the ambient reduction of N2 and CO at its cofactor site. Herein we present a biochemical and spectroscopic characterization of an Azotobacter vinelandii V nitrogenase variant expressing a citrate-substituted cofactor. Designated VnfDGKCit , the catalytic component of this V nitrogenase variant has an αβ2 (δ) subunit composition and carries an 8Fe P* cluster and a citrate-substituted V cluster analogue in the αβ dimer, as well as a 4Fe cluster in the "orphaned" β-subunit. Interestingly, when normalized based on the amount of cofactor, VnfDGKCit shows a shift of N2 reduction from H2 evolution toward NH3 formation and an opposite shift of CO reduction from hydrocarbon formation toward H2 evolution. These observations point to a role of the organic ligand in proton delivery during catalysis and imply the use of different reaction sites/mechanisms by nitrogenase for different substrate reductions. Moreover, the increased NH3 /H2 ratio upon citrate substitution suggests the possibility to modify the organic ligand for improved ammonia synthesis in the future. |
| Doi | 10.1002/cbic.201900654 |
| Pmid | 31747483 |
| Wosid | WOS:000502663200001 |
| Is Certified Translation | No |
| Dupe Override | No |
| Is Public | Yes |
| Language Text | English |