Azotobacter vinelandii scaffold protein NifU transfers iron to NifQ as part of the iron-molybdenum cofactor biosynthesis pathway for nitrogenase

Barahona , EmmaCollanstes García, Juan AndrésRosa-Núñez, ElenaXiong, JinJiang, XiJiménez-Vicente, EmilioEchávarri-Erasun, CarlosGuo, YisongRubio, Luis MGonzález-Guerrero, Manuel2024-12-182024-12-182024-10-22Emma Barahona, Juan Andrés Collantes-García, Elena Rosa-Núñez, Jin Xiong, Xi Jiang, Emilio Jiménez-Vicente, Carlos Echávarri-Erasun, Yisong Guo, Luis M. Rubio, Manuel González-Guerrero, Azotobacter vinelandii scaffold protein NifU transfers iron to NifQ as part of the iron-molybdenum cofactor biosynthesis pathway for nitrogenase, Journal of Biological Chemistry, Volume 300, Issue 11, 2024, 107900, ISSN 0021-9258, https://doi.org/10.1016/j.jbc.2024.107900.1083-351Xhttps://hdl.handle.net/10115/43137The authors would like to acknowledge Dr Isidro Abreu (CBGP, UPM-INIA/CSIC) for his help in the protein-protein interaction assays, Dr Lucía Payá (CBGP, UPM-INIA/CSIC) for providing pN2LP30, and Dr Dennis Dean and Ms Valerie L. Cash (Virginia Tech) for their gift of the SNifQ, NifUS, and SNifS expressing plasmids.The Azotobacter vinelandii molybdenum nitrogenase obtains molybdenum from NifQ, a monomeric iron-sulfur molybdoprotein. This protein requires an existing [Fe-S] cluster to form a [Mo-Fe3-S4] group, which acts as a specific molybdenum donor during nitrogenase FeMo-co biosynthesis. Here, we show biochemical evidence supporting the role of NifU as the [Fe-S] cluster donor. Protein-protein interaction studies involving apo-NifQ and as-isolated NifU demonstrated their interaction, which was only effective when NifQ lacked its [Fe-S] cluster. Incubation of apo-NifQ with [Fe4-S4]-loaded NifU increased the iron content of the former, contingent on both proteins being able to interact with one another. As a result of this interaction, a [Fe4-S4] cluster was transferred from NifU to NifQ. In A. vinelandii, NifQ was preferentially metalated by NifU rather than by the [Fe-S] cluster scaffold protein IscU. These results indicate the necessity of co-expressing NifU and NifQ to efficiently provide molybdenum for FeMo-co biosynthesis when engineering nitrogenase in plants.enAttribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/ironiron-sulfur proteinmolybdenumnitrogen fixationnitrogenaseAzotobacter vinelandii scaffold protein NifU transfers iron to NifQ as part of the iron-molybdenum cofactor biosynthesis pathway for nitrogenaseArticlehttps://doi.org/10.1016/j.jbc.2024.107900info:eu-repo/semantics/openAccess