BCAT2_HUMLU
ID BCAT2_HUMLU Reviewed; 408 AA.
AC K7QHS5;
DT 15-MAR-2017, integrated into UniProtKB/Swiss-Prot.
DT 06-FEB-2013, sequence version 1.
DT 03-AUG-2022, entry version 36.
DE RecName: Full=Branched-chain amino acid aminotransferase 2, chloroplastic {ECO:0000303|PubMed:23347725};
DE Short=HlBCAT2 {ECO:0000303|PubMed:23347725};
DE EC=2.6.1.42 {ECO:0000269|PubMed:23347725};
DE Flags: Precursor;
GN Name=BCAT2 {ECO:0000303|PubMed:23347725};
OS Humulus lupulus (European hop).
OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta;
OC Spermatophyta; Magnoliopsida; eudicotyledons; Gunneridae; Pentapetalae;
OC rosids; fabids; Rosales; Cannabaceae; Humulus.
OX NCBI_TaxID=3486;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE MRNA], TISSUE SPECIFICITY, FUNCTION,
RP CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, AND SUBCELLULAR
RP LOCATION.
RX PubMed=23347725; DOI=10.1186/1471-2229-13-12;
RA Clark S.M., Vaitheeswaran V., Ambrose S.J., Purves R.W., Page J.E.;
RT "Transcriptome analysis of bitter acid biosynthesis and precursor pathways
RT in hop (Humulus lupulus).";
RL BMC Plant Biol. 13:12-12(2013).
CC -!- FUNCTION: Converts 2-oxo acids to branched-chain amino acids. Shows no
CC kinetic preferences corresponding to anabolic or catabolic functions,
CC but likely involved in BCAA biosynthesis.
CC {ECO:0000269|PubMed:23347725}.
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2-oxoglutarate + L-isoleucine = (S)-3-methyl-2-oxopentanoate +
CC L-glutamate; Xref=Rhea:RHEA:24801, ChEBI:CHEBI:16810,
CC ChEBI:CHEBI:29985, ChEBI:CHEBI:35146, ChEBI:CHEBI:58045; EC=2.6.1.42;
CC Evidence={ECO:0000269|PubMed:23347725};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2-oxoglutarate + L-leucine = 4-methyl-2-oxopentanoate + L-
CC glutamate; Xref=Rhea:RHEA:18321, ChEBI:CHEBI:16810,
CC ChEBI:CHEBI:17865, ChEBI:CHEBI:29985, ChEBI:CHEBI:57427; EC=2.6.1.42;
CC Evidence={ECO:0000269|PubMed:23347725};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=2-oxoglutarate + L-valine = 3-methyl-2-oxobutanoate + L-
CC glutamate; Xref=Rhea:RHEA:24813, ChEBI:CHEBI:11851,
CC ChEBI:CHEBI:16810, ChEBI:CHEBI:29985, ChEBI:CHEBI:57762; EC=2.6.1.42;
CC Evidence={ECO:0000269|PubMed:23347725};
CC -!- COFACTOR:
CC Name=pyridoxal 5'-phosphate; Xref=ChEBI:CHEBI:597326;
CC Evidence={ECO:0000255|RuleBase:RU004516};
CC -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC Kinetic parameters:
CC KM=690 uM for glutamate {ECO:0000269|PubMed:23347725};
CC KM=120 uM for ketoisocarpoate {ECO:0000269|PubMed:23347725};
CC KM=160 uM for ketoisomethylvalerate {ECO:0000269|PubMed:23347725};
CC KM=200 uM for ketoisovalerate {ECO:0000269|PubMed:23347725};
CC KM=210 uM for 2-oxoglutarate {ECO:0000269|PubMed:23347725};
CC KM=280 uM for leucine {ECO:0000269|PubMed:23347725};
CC KM=250 uM for isoleucine {ECO:0000269|PubMed:23347725};
CC KM=130 uM for valine {ECO:0000269|PubMed:23347725};
CC Vmax=135.90 umol/min/mg enzyme with glutamate as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=119.20 umol/min/mg enzyme with ketoisocarpoate as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=84.68 umol/min/mg enzyme with ketoisomethylvalerate as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=96.38 umol/min/mg enzyme with ketoisovalerate as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=36.92 umol/min/mg enzyme with 2-oxoglutarate as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=43.43 umol/min/mg enzyme with leucine as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=88.08 umol/min/mg enzyme with isoleucine as substrate
CC {ECO:0000269|PubMed:23347725};
CC Vmax=23.29 umol/min/mg enzyme with valine as substrate
CC {ECO:0000269|PubMed:23347725};
CC -!- PATHWAY: Amino-acid biosynthesis; L-isoleucine biosynthesis; L-
CC isoleucine from 2-oxobutanoate: step 4/4. {ECO:0000305}.
CC -!- PATHWAY: Amino-acid biosynthesis; L-leucine biosynthesis; L-leucine
CC from 3-methyl-2-oxobutanoate: step 4/4. {ECO:0000305}.
CC -!- PATHWAY: Amino-acid biosynthesis; L-valine biosynthesis; L-valine from
CC pyruvate: step 4/4. {ECO:0000305}.
CC -!- SUBCELLULAR LOCATION: Plastid, chloroplast
CC {ECO:0000269|PubMed:23347725}.
CC -!- TISSUE SPECIFICITY: Expressed in lupulin glands and leaves.
CC {ECO:0000269|PubMed:23347725}.
CC -!- MISCELLANEOUS: Branched-chain amino acids are synthesized in
CC chloroplasts, whereas the degradation takes place in mitochondria.
CC {ECO:0000305}.
CC -!- SIMILARITY: Belongs to the class-IV pyridoxal-phosphate-dependent
CC aminotransferase family. {ECO:0000305}.
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DR EMBL; JQ063074; AFU07635.1; -; mRNA.
DR AlphaFoldDB; K7QHS5; -.
DR SMR; K7QHS5; -.
DR UniPathway; UPA00047; UER00058.
DR UniPathway; UPA00048; UER00073.
DR UniPathway; UPA00049; UER00062.
DR GO; GO:0009507; C:chloroplast; IEA:UniProtKB-SubCell.
DR GO; GO:0052656; F:L-isoleucine transaminase activity; IEA:UniProtKB-EC.
DR GO; GO:0052654; F:L-leucine transaminase activity; IEA:UniProtKB-EC.
DR GO; GO:0050048; F:L-leucine:2-oxoglutarate aminotransferase activity; IEA:RHEA.
DR GO; GO:0052655; F:L-valine transaminase activity; IEA:UniProtKB-EC.
DR GO; GO:0009097; P:isoleucine biosynthetic process; IEA:UniProtKB-UniPathway.
DR GO; GO:0009098; P:leucine biosynthetic process; IEA:UniProtKB-UniPathway.
DR GO; GO:0009099; P:valine biosynthetic process; IEA:UniProtKB-UniPathway.
DR CDD; cd01557; BCAT_beta_family; 1.
DR Gene3D; 3.20.10.10; -; 1.
DR Gene3D; 3.30.470.10; -; 1.
DR InterPro; IPR001544; Aminotrans_IV.
DR InterPro; IPR018300; Aminotrans_IV_CS.
DR InterPro; IPR036038; Aminotransferase-like.
DR InterPro; IPR005786; B_amino_transII.
DR InterPro; IPR043132; BCAT-like_C.
DR InterPro; IPR043131; BCAT-like_N.
DR InterPro; IPR033939; BCAT_family.
DR PANTHER; PTHR42825; PTHR42825; 1.
DR Pfam; PF01063; Aminotran_4; 1.
DR PIRSF; PIRSF006468; BCAT1; 1.
DR SUPFAM; SSF56752; SSF56752; 1.
DR TIGRFAMs; TIGR01123; ilvE_II; 1.
DR PROSITE; PS00770; AA_TRANSFER_CLASS_4; 1.
PE 1: Evidence at protein level;
KW Amino-acid biosynthesis; Aminotransferase;
KW Branched-chain amino acid biosynthesis; Chloroplast; Plastid;
KW Pyridoxal phosphate; Transferase; Transit peptide.
FT TRANSIT 1..58
FT /note="Chloroplast"
FT /evidence="ECO:0000255"
FT CHAIN 59..408
FT /note="Branched-chain amino acid aminotransferase 2,
FT chloroplastic"
FT /evidence="ECO:0000255"
FT /id="PRO_0000439268"
FT ACT_SITE 254
FT /note="Proton acceptor"
FT /evidence="ECO:0000250|UniProtKB:P19938"
FT BINDING 152
FT /ligand="pyridoxal 5'-phosphate"
FT /ligand_id="ChEBI:CHEBI:597326"
FT /evidence="ECO:0000250|UniProtKB:P19938"
FT BINDING 290
FT /ligand="pyridoxal 5'-phosphate"
FT /ligand_id="ChEBI:CHEBI:597326"
FT /evidence="ECO:0000250|UniProtKB:P19938"
FT MOD_RES 254
FT /note="N6-(pyridoxal phosphate)lysine"
FT /evidence="ECO:0000250|UniProtKB:P19938"
SQ SEQUENCE 408 AA; 44520 MW; 1369FF5F0D6B881F CRC64;
MDCAAALLPG FHPNYLLCPS RHFSSLLPKT DLSSPLKFQL QNKQLSLASS HGFSPVICNA
TLSDTYSETV ELADIDWDNL GFGFLPTDYM YNMKCAQGES FSNGELQRFG NIELSPSAGV
LNYGQGLFEG LKAYRKEDGN ILLFRPEENA LRMRLGAERM CMPSPTVDQF VDAVKATVLA
NKRWIPPVGK GSLYIRPLLM GSGAVLGLAP APEYTFLIYV SPVGNYFKEG VAPIHLIVED
NLHRATPGGT GGVKTIGNYA AVLKAQSAAK EQGYSDVLYL DCVHKKYLEE VSSCNIFVVK
GNLIFTPAIK GTILPGITRK SIIDVARTLG FQVEERLVHV DELLDADEVF CTGTAVVVSP
VGSITYHGER VPYNEGGVGA VSQQLYSALT RLQMGFIKDN MNWTVELS
