Database accession: MF7000541
Name: NfsA with Fumarate (Escherichia coli)
PDB ID: 8ajx
Experimental method: X-ray (1.25 Å)
Assembly: Homodimer
Source organism: Escherichia coli
Primary publication of the structure:
Day MA, Jarrom D, Rajah N, Searle PF, Hyde EI, White SA
Oxygen-insensitive nitroreductase E. coli NfsA, but not NfsB, is inhibited by fumarate.
(2022) Proteins :
PMID: 36443029
Abstract:
Escherichia coli NfsA and NfsB are founding members of two flavoprotein families that catalyze the oxygen-insensitive reduction of nitroaromatics and quinones by NAD(P)H. This reduction is required for the activity of nitrofuran antibiotics and the enzymes have also been proposed for use with nitroaromatic prodrugs in cancer gene therapy and biocatalysis, but the roles of the proteins in vivo in bacteria are not known. NfsA is NADPH-specific whereas NfsB can also use NADH. The crystal structures of E. coli NfsA and NfsB and several analogs have been determined previously. In our crystal trials, we unexpectedly observed NfsA bound to fumarate. We here present the X-ray structure of the E. coli NfsA-fumarate complex and show that fumarate acts as a weak inhibitor of NfsA but not of NfsB. The structural basis of this differential inhibition is conserved in the two protein families and occurs at fumarate concentrations found in vivo, so impacting the efficacy of these proteins.
Annotations from the GeneOntology database. Only terms that fit at least two of the interacting proteins are shown. Molecular function:
chromate reductase activity chromate reductase activity
FMN binding FMN binding
NAD(P)H dehydrogenase (quinone) activity NAD(P)H dehydrogenase (quinone) activity
protein homodimerization activity protein homodimerization activity
Biological process: not assigned
Cellular component:
cytosol cytosol
Structural annotations of the participating protein chains.Entry contents: 2 distinct polypeptide molecules
Chains: A, A-2
Notes: All chains according to the most probable oligomerization state stored in PDBe were considered.
Number of unique protein segments: 1
Name: Oxygen-insensitive NADPH nitroreductase
Source organism: Escherichia coli
Length: 240 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMTPTIELICGHRSIRHFTDEPISEAQREAIINSARATSSSSFLQCSSIIRITDKALREELVTLTGGQKHVAQAAEFWVFCADFNRHLQICPDAQLGLAEQLLLGVVDTAMMAQNALIAAESLGLGGVYIGGLRNNIEAVTKLLKLPQHVLPLFGLCLGWPADNPDLKPRLPASILVHENSYQPLDKGALAQYDEQLAEYYLTRGSNNRRDTWSDHIRRTIIKESRPFILDYLHKQGWATR
UniProtKB AC: P17117 (positions: 1-240)
Coverage: 100%
Name: Oxygen-insensitive NADPH nitroreductase
Source organism: Escherichia coli
Length: 240 residues
Sequence:Sequence according to the corresponding UniProt protein segmentMTPTIELICGHRSIRHFTDEPISEAQREAIINSARATSSSSFLQCSSIIRITDKALREELVTLTGGQKHVAQAAEFWVFCADFNRHLQICPDAQLGLAEQLLLGVVDTAMMAQNALIAAESLGLGGVYIGGLRNNIEAVTKLLKLPQHVLPLFGLCLGWPADNPDLKPRLPASILVHENSYQPLDKGALAQYDEQLAEYYLTRGSNNRRDTWSDHIRRTIIKESRPFILDYLHKQGWATR
UniProtKB AC: P17117 (positions: 1-240)
Coverage: 100%
Evidence demonstrating that the participating proteins are unstructured prior to the interaction and their folding is coupled to binding. Representative domain in related structures: Nitroreductase family
Evidence level: Indirect evidence
Evidence coverage: The full structure participates in mutual synergistic folding.
Complex Evidence:
Authors claim that the homodimeric NAD(P)H nitroreductase is a highly intertwined dimer with the FMN binding site lying at the dimer interface (PMID:18241886). Other structures belonging to the nitroreductase family also have an extensive interaction surface wherein a large hydrophobic solvent-accessible surface becomes buried upon dimer formation, suggesting that the monomers would be unstable on their own (PMID:16229462, PMID:19436071). Domain-swapping is also typical, where the extended C-terminal region extensively interacts with the core domain of the neighbouring monomer, forming an interlocked dimer (PMID:34473996, PMID:19436071, PMID:8885832).
Chain A:
N/A
Chain A-2:
N/A
Surface and contacts features:
Structures from the PDB that contain the same number of proteins, and the proteins from the two structures show a sufficient degree of pairwise similarity, i.e. they belong to the same UniRef90 cluster (the full proteins exhibit at least 90% sequence identity) and convey roughly the same region to their respective interactions (the two regions from the two proteins share a minimum of 70% overlap). Download the CIF file (.cif)
Download this entry's XML file (.xml)
Download this entry's JSON file (.json)
