Metal trafficking for nitrogen fixation: NifQ donates molybdenum to NifEN/NifH for the biosynthesis of the nitrogenase FeMo-cofactor

The molybdenum nitrogenase, present in a diverse group of bacteria and archea, is the major contributor to biological nitrogen fixation. The nitrogenase active site contains an iron-molybdenum cofactor (FeMo-co) composed of 7Fe, 9S, 1Mo, one unidentified light atom, and homocitrate. The nifQ gene wa...

Full description

Saved in:
Bibliographic Details
Published in:Proceedings of the National Academy of Sciences - PNAS 2008-08, Vol.105 (33), p.11679-11684
Main Authors: Hernandez, Jose A, Curatti, Leonardo, Aznar, Constantino P, Perova, Zinaida, Britt, R. David, Rubio, Luis M
Format: Article
Language:English
Subjects:
Atoms
Azotobacter vinelandii
Azotobacter vinelandii - genetics
Azotobacter vinelandii - metabolism
Bacteria
Bacterial Proteins - genetics
Bacterial Proteins - isolation & purification
Bacterial Proteins - metabolism
Biochemistry
Biological Sciences
Biological Transport
Biosynthesis
Coenzymes - genetics
Coenzymes - isolation & purification
Coenzymes - metabolism
Enzymes
Genes
Iron - metabolism
Iron-Sulfur Proteins - genetics
Iron-Sulfur Proteins - isolation & purification
Iron-Sulfur Proteins - metabolism
Line spectra
Metalloproteins - genetics
Metalloproteins - isolation & purification
Metalloproteins - metabolism
Molybdates
Molybdenum
Molybdenum - metabolism
Nitrogen
Nitrogen Fixation
Nitrogenase - metabolism
Protein Binding
Protein precursors
Pteridines - isolation & purification
Pteridines - metabolism
Transcription Factors - genetics
Transcription Factors - isolation & purification
Transcription Factors - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The molybdenum nitrogenase, present in a diverse group of bacteria and archea, is the major contributor to biological nitrogen fixation. The nitrogenase active site contains an iron-molybdenum cofactor (FeMo-co) composed of 7Fe, 9S, 1Mo, one unidentified light atom, and homocitrate. The nifQ gene was known to be involved in the incorporation of molybdenum into nitrogenase. Here we show direct biochemical evidence for the role of NifQ in FeMo-co biosynthesis. As-isolated NifQ was found to carry a molybdenum-iron-sulfur cluster that serves as a specific molybdenum donor for FeMo-co biosynthesis. Purified NifQ supported in vitro FeMo-co synthesis in the absence of an additional molybdenum source. The mobilization of molybdenum from NifQ required the simultaneous participation of NifH and NifEN in the in vitro FeMo-co synthesis assay, suggesting that NifQ would be the physiological molybdenum donor to a hypothetical NifEN/NifH complex.
ISSN:0027-8424
1091-6490
DOI:10.1073/pnas.0803576105