HNR_EUBBA
ID HNR_EUBBA Reviewed; 499 AA.
AC Q0QLF7;
DT 08-FEB-2011, integrated into UniProtKB/Swiss-Prot.
DT 05-SEP-2006, sequence version 1.
DT 03-AUG-2022, entry version 57.
DE RecName: Full=6-hydroxynicotinate reductase {ECO:0000312|EMBL:ABC88393.1};
DE EC=1.3.7.1;
GN Name=Hnr {ECO:0000312|EMBL:ABC88393.1};
OS Eubacterium barkeri (Clostridium barkeri).
OC Bacteria; Firmicutes; Clostridia; Eubacteriales; Eubacteriaceae;
OC Eubacterium.
OX NCBI_TaxID=1528;
RN [1] {ECO:0000305, ECO:0000312|EMBL:ABC88393.1}
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-26, COFACTOR,
RP PATHWAY, AND SUBUNIT.
RC STRAIN=ATCC 25849 / DSM 1223 / JCM 1389 / NCIMB 10623 / VKM B-1775 / VPI
RC 5359 {ECO:0000312|EMBL:ABC88393.1};
RX PubMed=16894175; DOI=10.1073/pnas.0601635103;
RA Alhapel A., Darley D.J., Wagener N., Eckel E., Elsner N., Pierik A.J.;
RT "Molecular and functional analysis of nicotinate catabolism in Eubacterium
RT barkeri.";
RL Proc. Natl. Acad. Sci. U.S.A. 103:12341-12346(2006).
RN [2] {ECO:0000305}
RP FUNCTION, CATALYTIC ACTIVITY, AND BIOPHYSICOCHEMICAL PROPERTIES.
RX PubMed=5767303; DOI=10.1016/s0021-9258(18)91830-2;
RA Holcenberg J.S., Tsai L.;
RT "Nicotinic acid metabolism. IV. Ferredoxin-dependent reduction of 6-
RT hydroxynicotinic acid to 6-oxo-1,4,5,6-tetrahydronicotinic acid.";
RL J. Biol. Chem. 244:1204-1211(1969).
CC -!- FUNCTION: Catalyzes the reversible reduction of 6-hydroxynicotinate to
CC 6-oxo-1,4,5,6-tetrahydronicotinate. {ECO:0000269|PubMed:5767303}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=1,4,5,6-tetrahydro-6-oxonicotinate + oxidized 2[4Fe-4S]-
CC [ferredoxin] = 6-hydroxynicotinate + 2 H(+) + reduced 2[4Fe-4S]-
CC [ferredoxin]; Xref=Rhea:RHEA:17225, Rhea:RHEA-COMP:10002, Rhea:RHEA-
CC COMP:10004, ChEBI:CHEBI:15378, ChEBI:CHEBI:33722, ChEBI:CHEBI:33723,
CC ChEBI:CHEBI:57664, ChEBI:CHEBI:57777; EC=1.3.7.1;
CC Evidence={ECO:0000269|PubMed:5767303};
CC -!- COFACTOR:
CC Name=an oxidized flavin; Xref=ChEBI:CHEBI:60531;
CC Evidence={ECO:0000269|PubMed:16894175};
CC Note=Binds 1 flavin covalently per subunit.
CC {ECO:0000269|PubMed:16894175};
CC -!- COFACTOR:
CC Name=[2Fe-2S] cluster; Xref=ChEBI:CHEBI:190135;
CC Evidence={ECO:0000269|PubMed:16894175};
CC Note=Binds 1 [2Fe-2S] cluster per subunit.
CC {ECO:0000269|PubMed:16894175};
CC -!- COFACTOR:
CC Name=[4Fe-4S] cluster; Xref=ChEBI:CHEBI:49883;
CC Evidence={ECO:0000269|PubMed:16894175};
CC Note=Binds 2 [4Fe-4S] clusters per subunit.
CC {ECO:0000269|PubMed:16894175};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=16 uM for reduced ferrodoxin {ECO:0000269|PubMed:5767303};
CC pH dependence:
CC Optimum pH for the reduction of 6-hydroxynicotinate is 6.5. Activity
CC declines rapidly below pH 5.6. {ECO:0000269|PubMed:5767303};
CC -!- PATHWAY: Cofactor degradation; nicotinate degradation; propanoate and
CC pyruvate from 6-hydroxynicotinate: step 1/8.
CC {ECO:0000269|PubMed:16894175}.
CC -!- SUBUNIT: Homotetramer. {ECO:0000269|PubMed:16894175}.
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DR EMBL; DQ310789; ABC88393.1; -; Genomic_DNA.
DR AlphaFoldDB; Q0QLF7; -.
DR STRING; 1528.SAMN04488579_11219; -.
DR KEGG; ag:ABC88393; -.
DR BioCyc; MetaCyc:MON-13675; -.
DR UniPathway; UPA01010; UER01012.
DR GO; GO:0051537; F:2 iron, 2 sulfur cluster binding; IEA:UniProtKB-KW.
DR GO; GO:0051539; F:4 iron, 4 sulfur cluster binding; IEA:UniProtKB-KW.
DR GO; GO:0047595; F:6-hydroxynicotinate reductase activity; IDA:UniProtKB.
DR GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR GO; GO:1901848; P:nicotinate catabolic process; IDA:UniProtKB.
DR InterPro; IPR017896; 4Fe4S_Fe-S-bd.
DR InterPro; IPR017900; 4Fe4S_Fe_S_CS.
DR Pfam; PF00037; Fer4; 2.
DR PROSITE; PS00198; 4FE4S_FER_1; 1.
DR PROSITE; PS51379; 4FE4S_FER_2; 2.
PE 1: Evidence at protein level;
KW 2Fe-2S; 4Fe-4S; Direct protein sequencing; Iron; Iron-sulfur;
KW Metal-binding; Oxidoreductase; Repeat.
FT CHAIN 1..499
FT /note="6-hydroxynicotinate reductase"
FT /id="PRO_0000403975"
FT DOMAIN 1..29
FT /note="4Fe-4S ferredoxin-type 1"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00711"
FT DOMAIN 31..61
FT /note="4Fe-4S ferredoxin-type 2"
FT /evidence="ECO:0000255|PROSITE-ProRule:PRU00711"
FT BINDING 9
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 12
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 15
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 19
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 41
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 44
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 47
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00195"
FT BINDING 51
FT /ligand="[4Fe-4S] cluster"
FT /ligand_id="ChEBI:CHEBI:49883"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00195"
SQ SEQUENCE 499 AA; 53097 MW; 211F9BB464FEF5F8 CRC64;
MFKIDEEKCK KCRMCVKECP VHAVYYEKKD KGAIVEITEK CVECGICKRV CKFGAIENDA
PLESVITCSS CPIQCKVPLG ETGACTRYRN VGGKLVRDRE LVVEALEQKE AADNIKKPII
TAVGAGTNYP CSKPAPHIVS ECRDGVDVVT VVTEAPLSYS GLVIKLDTNT YIGEEGDPVY
RDGKVVGMVN TEEYGSKMIA IGGANRLTGD NGFATARTIV ELANGEEVEL KVNKKIVLKL
KAGVAPVIDG VEESIMRIGC GSATVGLFAK RMKDAVDECI VIDHHVIGLC SEHLAGEAVG
MTWSGIIPNA TKSSRGRYFG GHGSGIGGTS LETPRDAIKG ADMSIAKAGM QVMVVNTTGE
IYALFELKAD GSFDEIPMTE AALGVALAIQ DNCQRSMTSI LYTGGTGGSA RGGVCTHPVK
ITEAVHEQKA VLTIGGAPAF VYPGGGINFM VDTQKVVNKA FTWVPTPATV APVEYTMTVA
DYEAMGGHMD QIKDVSEYK
