ID   LDHB_TRASE              Reviewed;         333 AA.
AC   Q9PT42;
DT   16-NOV-2001, integrated into UniProtKB/Swiss-Prot.
DT   23-JAN-2007, sequence version 3.
DT   03-AUG-2022, entry version 102.
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   Trachemys scripta elegans (Red-eared slider turtle).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Archelosauria; Testudinata; Testudines; Cryptodira; Durocryptodira;
OC   Testudinoidea; Emydidae; Trachemys.
OX   NCBI_TaxID=31138;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Muscle;
RX   PubMed=9364765; DOI=10.1093/oxfordjournals.molbev.a025717;
RA   Mannen H., Tsoi S.C.-M., Krushkal J.S., Li W.-H., Li S.S.-L.;
RT   "The cDNA cloning and molecular evolution of reptile and pigeon lactate
RT   dehydrogenase isozymes.";
RL   Mol. Biol. Evol. 14:1081-1087(1997).
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; L79954; AAD46980.1; -; mRNA.
DR   AlphaFoldDB; Q9PT42; -.
DR   SMR; Q9PT42; -.
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_0000168473"
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;  36405 MW;  E7F27C32870F3D9D CRC64;
     MATLQEKLIT PIAAESTTPN NKITVVGVGQ VGMACAISIL GKGLCDELAL VDVWEDKLKG
     EMMDLQHGSL VLQTHKIVAD KDYAVTANSK IVVVTAGVRQ QEGESRLNLV QRNVNVFKFI
     IPQIMKYSPN CTILVVSNPV DILTYVTWKL SGLPKHRVIG SGCNLDSARF RHLMAEKLGI
     HPTSCHGWIL GEHGDSSVAV WSGVNVAGVS LQELNPAMGT DRDSENWKEV HKLVVDSAYE
     VIKLKGYTNW AIGFSVADLI ESMLKNLCRV HPVSTMVKGM YGIENEVFLS LPCVLSASGL
     TSVINQKLKD EEVAQLKKSA DTLWGIQKDL KDL