ID   STTH_STRNR              Reviewed;         252 AA.
AC   C5NU54;
DT   05-SEP-2012, integrated into UniProtKB/Swiss-Prot.
DT   01-SEP-2009, sequence version 1.
DT   25-MAY-2022, entry version 29.
DE   RecName: Full=Streptothricin hydrolase;
DE            EC=3.5.2.19;
GN   Name=sttH; Synonyms=sttH-sn;
OS   Streptomyces noursei.
OC   Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae;
OC   Streptomyces.
OX   NCBI_TaxID=1971;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND MUTAGENESIS OF CYS-158.
RC   STRAIN=ATCC 11455 / DSM 40635 / JCM 4922 / NBRC 15452 / NCIMB 8593 / NRRL
RC   B-1714;
RX   PubMed=19897889; DOI=10.1271/bbb.90499;
RA   Maruyama C., Hamano Y.;
RT   "The biological function of the bacterial isochorismatase-like hydrolase
RT   SttH.";
RL   Biosci. Biotechnol. Biochem. 73:2494-2500(2009).
CC   -!- FUNCTION: Catalyzes the hydrolysis of the amide bond of streptolidine
CC       lactam, thereby conferring streptothricin (ST) resistance. Can
CC       hydrolyze streptothricin-F and streptothricin-D. However, this strain
CC       is believed to be a ST nonproducer, which raises the possibility that
CC       its true role may not be its involvement in self-resistance to STs. May
CC       catalyze the hydrolysis of naturally occurring cyclic amide compounds
CC       that are structurally related to STs. {ECO:0000269|PubMed:19897889}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H2O + streptothricin F = streptothricin F acid;
CC         Xref=Rhea:RHEA:28138, ChEBI:CHEBI:15377, ChEBI:CHEBI:60822,
CC         ChEBI:CHEBI:60838; EC=3.5.2.19;
CC         Evidence={ECO:0000269|PubMed:19897889};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=1.3 mM for streptothricin-F {ECO:0000269|PubMed:19897889};
CC         KM=3.2 mM for streptothricin-D {ECO:0000269|PubMed:19897889};
CC         Vmax=13.0 umol/min/mg enzyme with streptothricin-F as substrate
CC         {ECO:0000269|PubMed:19897889};
CC         Vmax=16.2 umol/min/mg enzyme with streptothricin-D as substrate
CC         {ECO:0000269|PubMed:19897889};
CC       pH dependence:
CC         Optimum pH is 7.0. {ECO:0000269|PubMed:19897889};
CC       Temperature dependence:
CC         Optimum temperature is 55 degrees Celsius.
CC         {ECO:0000269|PubMed:19897889};
CC   -!- SIMILARITY: Belongs to the isochorismatase family. {ECO:0000305}.
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DR   EMBL; AB512090; BAH84826.1; -; Genomic_DNA.
DR   AlphaFoldDB; C5NU54; -.
DR   SMR; C5NU54; -.
DR   KEGG; ag:BAH84826; -.
DR   BRENDA; 3.5.2.19; 11755.
DR   GO; GO:0016812; F:hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in cyclic amides; IDA:UniProtKB.
DR   GO; GO:0046677; P:response to antibiotic; IEA:UniProtKB-KW.
DR   Gene3D; 3.40.50.850; -; 1.
DR   InterPro; IPR000868; Isochorismatase-like.
DR   InterPro; IPR036380; Isochorismatase-like_sf.
DR   Pfam; PF00857; Isochorismatase; 1.
DR   SUPFAM; SSF52499; SSF52499; 1.
PE   1: Evidence at protein level;
KW   Antibiotic resistance; Hydrolase.
FT   CHAIN           1..252
FT                   /note="Streptothricin hydrolase"
FT                   /id="PRO_0000418976"
FT   REGION          230..252
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        233..252
FT                   /note="Pro residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        158
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000305"
FT   MUTAGEN         158
FT                   /note="C->S: Loss of activity."
FT                   /evidence="ECO:0000269|PubMed:19897889"
SQ   SEQUENCE   252 AA;  26136 MW;  B40BBF4307DD849F CRC64;
     MIRPGRCLWQ PCLSGRKRSR PSGPVSRHGM MAAMTAPTAA AIRPVQALLV VDVQAAFVSG
     WEAVPDADRV LRCTRDLLSR ARAAGALVVH LQNDGEPGAV DAPHTPGWEL HLPVEPGPRE
     RVVRKTEDDG FADTPLGDLL TDAGVTELAV CGVLSEMCVA ATARTALVRG HRVVLPHDAH
     ATYDIPAAPG ISDTVPAAMS SRAAEWALGD EVEIVPHAAA VPFAAAPRPA VGPAAAPGLP
     VSPAAPPPSP VR