Nitrogen fixation negative regulator NifL (IPR014285)

Short name: N_fixation_neg-reg_NifL

Overlapping homologous superfamilies


Family relationships



NifL from Azotobacter vinelandii senses both the redox and fixed nitrogen status to regulate nitrogen fixation. NifL acts by modulating the activity of the nitrogen fixation positive regulator protein NifA: NifL inhibits NifA in response to oxygen and low level of fixed nitrogen. NifA and NifL are encoded by adjacent genes. NifL is FAD-containing, and has a domain architecture similar to that of the cytoplasmic histidine protein kinases, containing two N-terminal PAS domains and a C-terminal transmitter region containing a conserved histidine residue (H domain) and a nucleotide binding GHKL domain corresponding to the catalytic core of the histidine kinases [PMID: 17355964]. However, NifL does not exhibit kinase activity and regulates its partner NifA by direct protein-protein interactions rather than phosphorylation.

GO terms

Biological Process

GO:0009399 nitrogen fixation
GO:0007165 signal transduction

Molecular Function

GO:0050660 flavin adenine dinucleotide binding
GO:0004871 signal transducer activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.