ID   HYDRA_PSESN             Reviewed;         249 AA.
AC   Q00924;
DT   01-APR-1993, integrated into UniProtKB/Swiss-Prot.
DT   01-APR-1993, sequence version 1.
DT   03-AUG-2022, entry version 50.
DE   RecName: Full=Hydantoin racemase {ECO:0000303|PubMed:1339422};
DE            EC=5.1.99.5 {ECO:0000269|PubMed:1459947};
GN   Name=hyuE {ECO:0000303|PubMed:1339422};
OS   Pseudomonas sp. (strain NS671).
OG   Plasmid pHN671.
OC   Bacteria; Proteobacteria.
OX   NCBI_TaxID=29441;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, SUBSTRATE SPECIFICITY, AND
RP   NOMENCLATURE.
RC   STRAIN=NS671;
RX   PubMed=1339422; DOI=10.1128/jb.174.11.3461-3466.1992;
RA   Watabe K., Ishikawa T., Mukohara Y., Nakamura H.;
RT   "Identification and sequencing of a gene encoding a hydantoin racemase from
RT   the native plasmid of Pseudomonas sp. strain NS671.";
RL   J. Bacteriol. 174:3461-3466(1992).
RN   [2]
RP   PROTEIN SEQUENCE OF 1-10, FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL
RP   PROPERTIES, ACTIVITY REGULATION, AND SUBUNIT.
RC   STRAIN=NS671;
RX   PubMed=1459947; DOI=10.1128/jb.174.24.7989-7995.1992;
RA   Watabe K., Ishikawa T., Mukohara Y., Nakamura H.;
RT   "Purification and characterization of the hydantoin racemase of Pseudomonas
RT   sp. strain NS671 expressed in Escherichia coli.";
RL   J. Bacteriol. 174:7989-7995(1992).
CC   -!- FUNCTION: Involved in the asymmetric conversion of racemic 5-
CC       substituted hydantoins to the corresponding L-amino acids. Catalyzes
CC       the racemization via enolization of D- and L-5-monosubstituted
CC       hydantoins. Is able to racemize 5-substituted hydantoins having either
CC       aromatic or aliphatic substituents such as D- and L-5-(2-
CC       methylthioethyl)hydantoin. {ECO:0000269|PubMed:1339422,
CC       ECO:0000269|PubMed:1459947}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a D-5-monosubstituted hydantoin = a L-5-monosubstituted
CC         hydantoin; Xref=Rhea:RHEA:46624, ChEBI:CHEBI:86339,
CC         ChEBI:CHEBI:86340; EC=5.1.99.5;
CC         Evidence={ECO:0000269|PubMed:1459947};
CC   -!- ACTIVITY REGULATION: Strongly inhibited by Cu(2+) and Zn(2+). Slightly
CC       stimulated by of Mn(2+) or Co(2+), but also by metal-chelating agents
CC       such as EDTA or EGTA. {ECO:0000269|PubMed:1459947}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         Vmax=79 umol/min/mg enzyme with L-5-(2-methylthioethyl)hydantoin as
CC         substrate {ECO:0000269|PubMed:1459947};
CC         Vmax=35.2 umol/min/mg enzyme with D-5-(2-methylthioethyl)hydantoin as
CC         substrate {ECO:0000269|PubMed:1459947};
CC       pH dependence:
CC         Optimum pH is 9.5. {ECO:0000269|PubMed:1459947};
CC       Temperature dependence:
CC         Optimum temperature is 45 degrees Celsius.
CC         {ECO:0000269|PubMed:1459947};
CC   -!- SUBUNIT: Homohexamer. {ECO:0000269|PubMed:1459947}.
CC   -!- SIMILARITY: Belongs to the HyuE racemase family. {ECO:0000305}.
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DR   EMBL; M84731; AAA25843.1; -; Genomic_DNA.
DR   PIR; B41895; B41895.
DR   AlphaFoldDB; Q00924; -.
DR   SMR; Q00924; -.
DR   BioCyc; MetaCyc:MON-14268; -.
DR   BRENDA; 5.1.99.5; 5085.
DR   GO; GO:0036348; F:hydantoin racemase activity; IDA:UniProtKB.
DR   GO; GO:0036361; F:racemase activity, acting on amino acids and derivatives; IEA:InterPro.
DR   GO; GO:0008652; P:cellular amino acid biosynthetic process; IEA:UniProtKB-KW.
DR   InterPro; IPR015942; Asp/Glu/hydantoin_racemase.
DR   Pfam; PF01177; Asp_Glu_race; 1.
PE   1: Evidence at protein level;
KW   Amino-acid biosynthesis; Direct protein sequencing; Isomerase; Plasmid.
FT   CHAIN           1..249
FT                   /note="Hydantoin racemase"
FT                   /id="PRO_0000084120"
FT   SITE            76
FT                   /note="Seems to be responsible for recognition and proton
FT                   retrieval of D-isomers"
FT                   /evidence="ECO:0000250|UniProtKB:Q6TMG4"
FT   SITE            181
FT                   /note="Seems to be responsible for L-isomers recognition
FT                   and racemization"
FT                   /evidence="ECO:0000250|UniProtKB:Q6TMG4"
SQ   SEQUENCE   249 AA;  27090 MW;  FC9A3E9E81485317 CRC64;
     MKIKVINPNT TLAMTKGIEH AAKSAARSDT QIVAVSPKMG PASIESYYDE YLSIPGVIEE
     IKKGEEEGVD AFVIACWGDP GLHAAREVTD KPVVGIAESS VYLASMLAAR FSVVTVLPRI
     KTMLEDLVDS YGMQKRVLNI RTTPMGVLDF ERDPEAGIEM LRQEGKRAVE EDNAEAILLG
     CAGMAEFADS LEKELGVPVI DGVVAGVKFA ETIVDLGKKT SKLKTYKYPE KKEYVGALEN
     FGRNQTTTK