Reviewed, UniProtKB/Swiss-Prot P38489 (NFNB_ECOLI)

Names and origin

Protein names

Recommended name:
    Oxygen-insensitive NAD(P)H nitroreductase
    EC=1.-.-.-
Alternative name(s):
    FMN-dependent nitroreductase
    Dihydropteridine reductase
    EC=1.5.1.34

Gene names

Name:	nfnB
Synonyms:	dprA, nfsB, nfsI, ntr
Ordered Locus Names:	b0578, JW0567

Organism

Escherichia coli (strain K12) [Complete proteome] [HAMAP]

Taxonomic identifier

83333 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

Protein attributes

Sequence length	217 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Reduction of a variety of nitroaromatic compounds using NADH (and to lesser extent NADPH) as source of reducing equivalents; two electrons are transferred. Capable of reducing nitrofurazone, quinones and the anti-tumor agent CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide). The reduction of CB1954 results in the generation of cytotoxic species.
Catalytic activity	A 5,6,7,8-tetrahydropteridine + NAD(P)(+) = a 6,7-dihydropteridine + NAD(P)H.
Cofactor	FMN.
Enzyme regulation	Subject to competitive inhibition by dicoumarol, nicotinic acid and acetate with respect to NADH. Subject to uncompetitive inhibition by dicoumarol, nicotinic acid and acetate with respect to nitrofurazone and nitrofurantoin.
Subunit structure	Homodimer.
Sequence similarities	Belongs to the nitroreductase family.
Biophysicochemical properties	Kinetic parameters: KM=350 µM for NADH KM=1850 µM for nitrofurazone

Ontologies

Keywords
Ligand	FMN Flavoprotein NAD NADP
Molecular function	Oxidoreductase
Technical term	3D-structure Complete proteome Direct protein sequencing
Gene Ontology (GO)
Biological process	oxidation reduction Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	cytosol Inferred from direct assay. Source: UniProtKB mitochondrion Inferred from direct assay. Source: UniProtKB
Molecular function	6,7-dihydropteridine reductase activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

Feature key

Position(s)

Length

Description

Graphical view

Feature identifier

Molecule processing

Chain

1 – 217

217

Oxygen-insensitive NAD(P)H nitroreductase

PRO_0000072711

Regions

Nucleotide binding

10 – 14

5

FMN

Nucleotide binding

153 – 158

6

NAD or NADP By similarity

Nucleotide binding

165 – 166

2

FMN

Nucleotide binding

205 – 207

3

FMN

Sites

Binding site

41

1

NAD or NADP; via amide nitrogen

Binding site

71

1

FMN

Experimental info

Sequence conflict

5

1

S → C AA sequence Ref.9

Sequence conflict

10 – 12

3

RHS → CIV AA sequence Ref.9

Sequence conflict

19

1

S → M AA sequence Ref.9

Sequence conflict

21

1

Missing AA sequence Ref.7

Sequence conflict

28

1

E → D AA sequence Ref.7

Sequence conflict

180

1

E → I AA sequence Ref.7

Secondary structure

1

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217

Helix Strand Turn

Details...

Helix

3 – 9

7

Helix

24 – 35

12

Helix

40 – 42

3

Beta strand

46 – 51

6

Helix

54 – 61

8

Helix

66 – 71

6

Helix

72 – 77

6

Beta strand

78 – 89

12

Helix

92 – 104

13

Helix

111 – 129

19

Turn

130 – 132

3

Helix

135 – 157

23

Helix

169 – 175

7

Helix

179 – 181

3

Beta strand

183 – 192

10

Helix

199 – 201

3

Helix

210 – 213

4

Beta strand

214 – 216

3

Sequences

	Sequence		Length	Mass (Da)
	P38489-1 [UniParc]. Last modified October 1, 1994. Version 1. Checksum: A516CEFC3D46AEAC	FASTA	217	23,905
	10 20 30 40 50 60 MDIISVALKR HSTKAFDASK KLTPEQAEQI KTLLQYSPSS TNSQPWHFIV ASTEEGKARV 70 80 90 100 110 120 AKSAAGNYVF NERKMLDASH VVVFCAKTAM DDVWLKLVVD QEDADGRFAT PEAKAANDKG 130 140 150 160 170 180 RKFFADMHRK DLHDDAEWMA KQVYLNVGNF LLGVAALGLD AVPIEGFDAA ILDAEFGLKE 190 200 210 KGYTSLVVVP VGHHSVEDFN ATLPKSRLPQ NITLTEV

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"Gene cloning, purification, and characterization of NfsB, a minor oxygen-insensitive nitroreductase from Escherichia coli, similar in biochemical properties to FRase I, the major flavin reductase in Vibrio fischeri." Zenno S., Koike H., Tanokura M., Saigo K. J. Biochem. 120:736-744(1996) [PubMed: 8947835] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: K12 / C600 / ATCC 23724 / DSM 3925 / LMG 3041 / NCIB 10222.
[2]	"Physical characterisation of the Escherichia coli B gene encoding nitroreductase and its over-expression in Escherichia coli K12." Michael N.P., Brehm J.K., Anlezark G.M., Minton N.P. FEMS Microbiol. Lett. 124:195-202(1994) [PubMed: 7813889] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA]. Strain: B.
[3]	"A 718-kb DNA sequence of the Escherichia coli K-12 genome corresponding to the 12.7-28.0 min region on the linkage map." Oshima T., Aiba H., Baba T., Fujita K., Hayashi K., Honjo A., Ikemoto K., Inada T., Itoh T., Kajihara M., Kanai K., Kashimoto K., Kimura S., Kitagawa M., Makino K., Masuda S., Miki T., Mizobuchi K. , Mori H., Motomura K., Nakamura Y., Nashimoto H., Nishio Y., Saito N., Sampei G., Seki Y., Tagami H., Takemoto K., Wada C., Yamamoto Y., Yano M., Horiuchi T. DNA Res. 3:137-155(1996) [PubMed: 8905232] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[4]	"Sequence of minutes 4-25 of Escherichia coli." Chung E., Allen E., Araujo R., Aparicio A.M., Davis K., Duncan M., Federspiel N., Hyman R., Kalman S., Komp C., Kurdi O., Lew H., Lin D., Namath A., Oefner P., Roberts D., Schramm S., Davis R.W. Submitted (JAN-1997) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[5]	"The complete genome sequence of Escherichia coli K-12." Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y. Science 277:1453-1474(1997) [PubMed: 9278503] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[6]	"Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110." Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T. Mol. Syst. Biol. 2:E1-E5(2006) [PubMed: 16738553] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[7]	"The bioactivation of 5-(aziridin-1-yl)-2,4-dinitrobenzamide (CB1954) -- I. Purification and properties of a nitroreductase enzyme from Escherichia coli -- a potential enzyme for antibody-directed enzyme prodrug therapy (ADEPT)." Anlezark G.M., Melton R.G., Sherwood R.F., Coles B., Friedlos F., Knox R.J. Biochem. Pharmacol. 44:2289-2295(1992) [PubMed: 1472094] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-31 AND 139-180, CHARACTERIZATION. Strain: B.
[8]	"Comparing the predicted and observed properties of proteins encoded in the genome of Escherichia coli K-12." Link A.J., Robison K., Church G.M. Electrophoresis 18:1259-1313(1997) [PubMed: 9298646] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-12. Strain: K12 / EMG2.
[9]	"Dihydropteridine reductase from Escherichia coli." Vasudevan S.G., Shaw D.C., Armarego W.L.F. Biochem. J. 255:581-588(1988) [PubMed: 3060113] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-20, CHARACTERIZATION AS A DIHYDROPTERIDINE REDUCT.
[10]	"Crystal structure of FMN-dependent nitroreductase from Escherichia coli B: a prodrug-activating enzyme." Parkinson G.N., Skelly J.V., Neidle S. J. Med. Chem. 43:3624-3631(2000) [PubMed: 11020276] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.06 ANGSTROMS) IN COMPLEX WITH FMN, SUBUNIT. Strain: B.
[11]	"The structure of Escherichia coli nitroreductase complexed with nicotinic acid: three crystal forms at 1.7 A, 1.8 A and 2.4 A resolution." Lovering A.L., Hyde E.I., Searle P.F., White S.A. J. Mol. Biol. 309:203-213(2001) [PubMed: 11491290] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) IN COMPLEX WITH NICOTININC ACID AND FMN, SUBUNIT. Strain: K12 / DH5-alpha.
[12]	"Studies on the nitroreductase prodrug-activating system. Crystal structures of complexes with the inhibitor dicoumarol and dinitrobenzamide prodrugs and of the enzyme active form." Johansson E., Parkinson G.N., Denny W.A., Neidle S. J. Med. Chem. 46:4009-4020(2003) [PubMed: 12954054] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) IN COMPLEXES WITH FMN; DICOUMAROL AND DINITROBENZAMIDE PRODRUGS, SUBUNIT.
[13]	"Structural and mechanistic studies of Escherichia coli nitroreductase with the antibiotic nitrofurazone. Reversed binding orientations in different redox states of the enzyme." Race P.R., Lovering A.L., Green R.M., Ossor A., White S.A., Searle P.F., Wrighton C.J., Hyde E.I. J. Biol. Chem. 280:13256-13264(2005) [PubMed: 15684426] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.7 ANGSTROMS) IN COMPLEX WITH FMN; ACETATE AND THE ANTIBIOTIC NITROFURAZONE, FUNCTION, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES.

Cross-references

Sequence databases

EMBLGenBankDDBJ

D25414 Genomic DNA. Translation: BAA05004.1.
U07860 Genomic DNA. Translation: AAC43263.1.
U82598 Genomic DNA. Translation: AAB40776.1.
U00096 Genomic DNA. Translation: AAC73679.1.
AP009048 Genomic DNA. Translation: BAA35218.1.

PIR

I67685.
S01818.

RefSeq

AP_001223.1.
NP_415110.1.

3D structure databases

PDBMSD

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1DS7	X-ray	2.06	A/B	1-217	[»]
1ICR	X-ray	1.70	A/B	1-217	[»]
1ICU	X-ray	1.80	A/B/C/D	1-217	[»]
1ICV	X-ray	2.40	A/B/C/D	1-217	[»]
1IDT	X-ray	2.00	A/B	1-217	[»]
1OO5	X-ray	2.50	A/B	1-217	[»]
1OO6	X-ray	2.00	A/B	1-217	[»]
1OON	X-ray	2.49	A/B	1-217	[»]
1OOQ	X-ray	2.00	A/B	1-217	[»]
1YKI	X-ray	1.70	A/B/C/D	1-217	[»]
1YLR	X-ray	1.70	A/B	1-217	[»]
1YLU	X-ray	2.00	A/B	1-217	[»]

ModBase

Search...

Protein-protein interaction databases

DIP

DIP:10330N.

IntAct

P38489.

2-D gel databases

SWISS-2DPAGE

P38489.

Genome annotation databases

GeneID

945778.

GenomeReviews

Gene locus b0578 in contig U00096_GR.
Gene locus JW0567 in contig AP009048_GR.

KEGG

ecj:JW0567.
eco:b0578.

Organism-specific databases

EchoBASE

EB4146.

EcoGene

EG20151. nfnB.

CMR

Search...

Phylogenomic databases

HOGENOM

P38489.

Enzyme and pathway databases

BioCyc

EcoCyc:DIHYDROPTERIREDUCT-MON.
MetaCyc:DIHYDROPTERIREDUCT-MON.

Family and domain databases

InterPro

IPR000415. Nitroreductase.
[Graphical view]

Pfam

PF00881. Nitroreductase. 1 hit.
[Graphical view]

ProtoNet

Search...

Other Resources

DrugBank

DB01093. Dimethyl sulfoxide.

Entry information

Entry name

NFNB_ECOLI

Accession

Primary (citable) accession number: P38489
Secondary accession number(s): P19575

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1994
Last sequence update:	October 1, 1994
Last modified:	November 25, 2008
This is version 80 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)