ID   LDHB_CAICA              Reviewed;         333 AA.
AC   Q98SL1;
DT   16-NOV-2001, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 3.
DT   03-AUG-2022, entry version 96.
DE   RecName: Full=L-lactate dehydrogenase B chain;
DE            Short=LDH-B;
DE            EC=1.1.1.27 {ECO:0000250|UniProtKB:P07195};
GN   Name=LDHB;
OS   Caiman crocodilus apaporiensis (Rio Apaporis caiman).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Archelosauria; Archosauria; Crocodylia; Alligatoridae; Caimaninae; Caiman.
OX   NCBI_TaxID=157164;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Heart;
RX   PubMed=11722846; DOI=10.1016/s0378-1119(01)00746-6;
RA   Liao C.-H., Ho W.-Z., Huang H.-W., Kuo C.-H., Lee S.-C., Li S.S.-L.;
RT   "Lactate dehydrogenase genes of caiman and Chinese soft-shelled turtle,
RT   with emphasis on the molecular phylogenetics and evolution of reptiles.";
RL   Gene 279:63-67(2001).
CC   -!- FUNCTION: Interconverts simultaneously and stereospecifically pyruvate
CC       and lactate with concomitant interconversion of NADH and NAD(+).
CC       {ECO:0000250|UniProtKB:P07195}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=(S)-lactate + NAD(+) = H(+) + NADH + pyruvate;
CC         Xref=Rhea:RHEA:23444, ChEBI:CHEBI:15361, ChEBI:CHEBI:15378,
CC         ChEBI:CHEBI:16651, ChEBI:CHEBI:57540, ChEBI:CHEBI:57945; EC=1.1.1.27;
CC         Evidence={ECO:0000250|UniProtKB:P07195};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:23445;
CC         Evidence={ECO:0000250|UniProtKB:P07195};
CC       PhysiologicalDirection=right-to-left; Xref=Rhea:RHEA:23446;
CC         Evidence={ECO:0000250|UniProtKB:P07195};
CC   -!- PATHWAY: Fermentation; pyruvate fermentation to lactate; (S)-lactate
CC       from pyruvate: step 1/1. {ECO:0000250|UniProtKB:P07195}.
CC   -!- SUBUNIT: Homotetramer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the LDH/MDH superfamily. LDH family.
CC       {ECO:0000305}.
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DR   EMBL; AF363793; AAK37571.1; -; mRNA.
DR   AlphaFoldDB; Q98SL1; -.
DR   SMR; Q98SL1; -.
DR   PRIDE; Q98SL1; -.
DR   UniPathway; UPA00554; UER00611.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0004459; F:L-lactate dehydrogenase activity; IEA:UniProtKB-EC.
DR   GO; GO:0019752; P:carboxylic acid metabolic process; IEA:InterPro.
DR   Gene3D; 3.90.110.10; -; 1.
DR   HAMAP; MF_00488; Lactate_dehydrog; 1.
DR   InterPro; IPR001557; L-lactate/malate_DH.
DR   InterPro; IPR011304; L-lactate_DH.
DR   InterPro; IPR018177; L-lactate_DH_AS.
DR   InterPro; IPR022383; Lactate/malate_DH_C.
DR   InterPro; IPR001236; Lactate/malate_DH_N.
DR   InterPro; IPR015955; Lactate_DH/Glyco_Ohase_4_C.
DR   InterPro; IPR036291; NAD(P)-bd_dom_sf.
DR   Pfam; PF02866; Ldh_1_C; 1.
DR   Pfam; PF00056; Ldh_1_N; 1.
DR   PIRSF; PIRSF000102; Lac_mal_DH; 1.
DR   PRINTS; PR00086; LLDHDRGNASE.
DR   SUPFAM; SSF51735; SSF51735; 1.
DR   SUPFAM; SSF56327; SSF56327; 1.
DR   TIGRFAMs; TIGR01771; L-LDH-NAD; 1.
DR   PROSITE; PS00064; L_LDH; 1.
PE   2: Evidence at transcript level;
KW   Cytoplasm; NAD; Oxidoreductase.
FT   INIT_MET        1
FT                   /note="Removed"
FT                   /evidence="ECO:0000250"
FT   CHAIN           2..333
FT                   /note="L-lactate dehydrogenase B chain"
FT                   /id="PRO_0000168469"
FT   ACT_SITE        193
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250"
FT   BINDING         29..57
FT                   /ligand="NAD(+)"
FT                   /ligand_id="ChEBI:CHEBI:57540"
FT                   /evidence="ECO:0000250"
FT   BINDING         99
FT                   /ligand="NAD(+)"
FT                   /ligand_id="ChEBI:CHEBI:57540"
FT                   /evidence="ECO:0000250"
FT   BINDING         106
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         138
FT                   /ligand="NAD(+)"
FT                   /ligand_id="ChEBI:CHEBI:57540"
FT                   /evidence="ECO:0000250"
FT   BINDING         138
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         169
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
FT   BINDING         248
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   333 AA;  36553 MW;  64FA7CC6C633044D CRC64;
     MATLKEKLIT HIASESTIPN NKVTVVGVGQ VGMACAVSIL GKSLCDELAL VDVLEDKLKG
     EMMDLQHGSL FLQTHKIVAD KDYAVTANSK IVVVTAGVRQ QEGESRLNLV QRNVNVFKFI
     IPQIIKYSPD CIILVVSNPV DILTYVTWKL SGLPKHRVIG SGCNLDSARF RYLMSEKLGI
     HPSSCHGWIL GEHGDSSVAV WSGVNVAGVS LQELNPAMGT DRDSEKWKEV HKQVVESAYE
     VIKLKGYTNW AIGFSVADLL ETMMKNLNRV QPVSTMVKGM YGIENEVFLS LPCVLSASGL
     TSVINQKLKD DEVAQLRSSA DTLWSIQKDL KDL