FUNCTION: Catalytic subunit of the periplasmic nitrate reductase (NAP). Only expressed at high levels during aerobic growth. NapAB complex receives electrons from the membrane-anchored tetraheme protein napC, thus allowing electron flow between membrane and periplasm. Essential function for nitrate assimilation and may have a role in anaerobic metabolism (By similarity).
CATALYTIC ACTIVITY: Nitrite + acceptor = nitrate + reduced acceptor.
COFACTOR: Binds 1 4Fe-4S cluster (By similarity).
COFACTOR: Binds 1 molybdenum ion per subunit (By similarity).
COFACTOR: Binds 2 molybdopterin guanine dinucleotide (MGD) groups per subunit (By similarity).
SUBUNIT: Interacts with napB (By similarity).
SUBCELLULAR LOCATION: Periplasm (By similarity).
PTM: Predicted to be exported by the Tat system. The position of the signal peptide cleavage has not been experimentally proven.
SIMILARITY: Belongs to the prokaryotic molybdopterin-containing oxidoreductase family. NasA/napA/narB subfamily.

Copyright

Copyrighted by the UniProt Consortium, see http://www.uniprot.org/terms. Distributed under the Creative Commons Attribution-NoDerivs License.

Cross-references

Sequence databases

EMBL

CP000301; ABD86522.1; -; Genomic_DNA.

[EMBL / GenBank / DDBJ] [CoDingSequence]

RefSeq

YP_530841.1; -.

3D structure databases

SMR

Q21AR4; 44-833.

ModBase

Q21AR4.

Enzyme and pathway databases

BioCyc

RPAL316056:RPC_0952-MON; -.

Ontologies

GO:0009055;	Molecular function: electron carrier activity (inferred from electronic annotation from HAMAP).
GO:0005506;	Molecular function: iron ion binding (inferred from electronic annotation from HAMAP).
GO:0008940;	Molecular function: nitrate reductase activity (inferred from electronic annotation from HAMAP).
GO:0006777;	Biological process: Mo-molybdopterin cofactor biosynthetic process (inferred from electronic annotation from HAMAP).
GO:0042128;	Biological process: nitrate assimilation (inferred from electronic annotation from HAMAP).
QuickGo view.

Family and domain databases

HAMAP

MF_01630; -; 1.
PBIL [Tree]

InterPro

IPR009010; Asp_de-COase-like_fold.
IPR006656; Mopterin_OxRdtase.
IPR006963; Mopterin_OxRdtase_Fe4S4.
IPR006655; Mopterin_OxRdtase_prok_CS.
IPR006657; MPT_dinuc_bd.
IPR010051; NO3_reductase_lsu_periplasm.
IPR006311; Tat.
Graphical view of domain structure.

Gene3D

G3DSA:2.40.40.20; Asp_decarboxylase-like_fold; 1.

Pfam

PF04879; Molybdop_Fe4S4; 1.
PF00384; Molybdopterin; 1.
PF01568; Molydop_binding; 1.
Pfam graphical view of domain structure.

TIGRFAMs

TIGR01706; NAPA; 1.
TIGR01409; TAT_signal_seq; 1.

PROSITE

PS00551; MOLYBDOPTERIN_PROK_1; 1.
PS00490; MOLYBDOPTERIN_PROK_2; FALSE_NEG.
PS00932; MOLYBDOPTERIN_PROK_3; FALSE_NEG.
PS51318; TAT; 1.
PROSITE graphical view of domain structure (profiles).

BLOCKS

Q21AR4.

Genome annotation databases

GeneID

3969715; -.

GenomeReviews

CP000301_GR; RPC_0952.

KEGG

rpc:RPC_0952; -.

Phylogenomic databases

HOGENOM

Q21AR4; -.

Genome annotation databases

CMR

Q21AR4; RPC_0952.

Other

ProtoNet

Q21AR4.

UniRef

View cluster of proteins with at least 50% / 90% / 100% identity.

Keywords

4Fe-4S; Complete proteome; Electron transport; Iron; Iron-sulfur; Metal-binding; Molybdenum; Nitrate assimilation; Oxidoreductase; Periplasm; Signal; Transport.

Features

Feature table viewer

`Key`	`From To`	`Length`	`Description`	`FTId`
`SIGNAL`	`1 33`	`33`	`Tat-type signal (Potential).`
`CHAIN`	`34 837`	`804`	`Periplasmic nitrate reductase.`	`PRO_0000256075`
`METAL`	`51 51`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`54 54`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`58 58`		`Iron-sulfur (4Fe-4S) (By similarity).`
`METAL`	`86 86`		`Iron-sulfur (4Fe-4S) (By similarity).`

Sequence information

Length: 837 AA [This is the length of the unprocessed precursor]

Molecular weight: 93633 Da [This is the MW of the unprocessed precursor]

CRC64: CA1EB7B6C1D9B06F [This is a checksum on the sequence]

        10         20         30         40         50         60 
MTTPKLDRRQ VLKLEAAAMA ALAGGIAMPA AAANLVTERA VSELKWDKAA CRFCGTGCSV 

        70         80         90        100        110        120 
MVATKENRVV ATHGDTKSEV NRGLNCVKGY FLSKIMYGHD RLTQPMLRKT DGKYDKNGEF 

       130        140        150        160        170        180 
MPVSWDEAFD IMAEKFKAAL KKRGPSGVGM FGSGQWTVWE GYAASKLFKA GFRSNNIDPN 

       190        200        210        220        230        240 
ARHCMASAVA GFMRTFGIDE PMGCYDDIEA ADVFVLWGSN MAEMHPLLWT RVTDRRLSAP 

       250        260        270        280        290        300 
HVKVAVLSTF EHRSFDLADL GLVFKPQTDL AILNAIANHI IKTGRVNKDF VAKHTTFKRG 

       310        320        330        340        350        360 
QTDIGYGLRP EHPLQKAATG AAKANDATDM SFEDYAAFVA DYTIEKASQI SGVPAAKIEA 

       370        380        390        400        410        420 
LAELYADPNT KVTSFWTMGF NQHTRGVWAN NLAYNLHLLT GKISEPGNSP FSLTGQPSAC 

       430        440        450        460        470        480 
GTAREVGTFS HRLPADMVVT NKKHRDIAEK IWKLPEGTIP DKPGYHAVLQ SRMLKDGLLN 

       490        500        510        520        530        540 
AYWVQVNNNL QAGANANEET YPGFRNPDNF IVVSDAYPSV TALAADLILP TAMWVEKEGA 

       550        560        570        580        590        600 
YGNAERRTQF WHQLVSAPGQ ARSDLWQLME FAKRFKIEEV WTEELLAKKP EVRGKTMYDV 

       610        620        630        640        650        660 
LYRNGQVDKY PSSDIEAGYL NDESKAFGYY VQKGLFEEYA SFGRGHGHDL APFDDYHRER 

       670        680        690        700        710        720 
GLRWPVVNGQ ETRWRFREGS DPYVQQGAGV QFYGFPDGRA RIFALPYEPA AEAPDAEFPF 

       730        740        750        760        770        780 
WLSTGRVLEH WHSGTMTRRV PELYKAFPEA VCFMHPDDAA ELKLRRGDEI KVESRRGFIR 

       790        800        810        820        830 
TRVETRGRNK PPRGLVFVPW FDEAQLINKV TLDATDPISL QTDYKKCAVR IERVTAS

Q21AR4 in FASTA format

View entry in original UniProtKB/Swiss-Prot format
View entry in raw text format (no links)
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	BLAST submission on ExPASy/SIB or at NCBI (USA)		Sequence analysis tools: ProtParam, ProtScale, Compute pI/Mw, PeptideMass, PeptideCutter, Dotlet (Java)
	ScanProsite, MotifScan		Submit a homology modeling request to SWISS-MODEL
	NPSA Sequence analysis tools