ID   AMYB_CYTFI              Reviewed;         468 AA.
AC   P96513;
DT   15-JUL-1999, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1997, sequence version 1.
DT   03-AUG-2022, entry version 81.
DE   RecName: Full=Beta-amylase;
DE            EC=3.2.1.2;
DE   AltName: Full=1,4-alpha-D-glucan maltohydrolase;
DE   Flags: Precursor; Fragment;
OS   Cytobacillus firmus (Bacillus firmus).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Bacillaceae; Cytobacillus.
OX   NCBI_TaxID=1399;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=725;
RX   PubMed=12549376;
RA   Chen W., He B., Lou X., Guan F., Ye C.;
RT   "Sequencing of a beta-amylase gene from Bacillus firmus.";
RL   Wei Sheng Wu Xue Bao 38:142-145(1998).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of (1->4)-alpha-D-glucosidic linkages in
CC         polysaccharides so as to remove successive maltose units from the
CC         non-reducing ends of the chains.; EC=3.2.1.2;
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108;
CC         Evidence={ECO:0000250|UniProtKB:P36924};
CC       Note=Binds 1 Ca(2+) ion per subunit. {ECO:0000250|UniProtKB:P36924};
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 14 family. {ECO:0000305}.
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DR   EMBL; AB000264; BAA19075.1; -; Genomic_DNA.
DR   AlphaFoldDB; P96513; -.
DR   SMR; P96513; -.
DR   CAZy; CBM25; Carbohydrate-Binding Module Family 25.
DR   CAZy; GH14; Glycoside Hydrolase Family 14.
DR   GO; GO:0102229; F:amylopectin maltohydrolase activity; IEA:UniProtKB-EC.
DR   GO; GO:0016161; F:beta-amylase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0000272; P:polysaccharide catabolic process; IEA:UniProtKB-KW.
DR   InterPro; IPR001554; Glyco_hydro_14.
DR   InterPro; IPR018238; Glyco_hydro_14_CS.
DR   InterPro; IPR000125; Glyco_hydro_14A_bac.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   PANTHER; PTHR31352; PTHR31352; 1.
DR   Pfam; PF01373; Glyco_hydro_14; 1.
DR   PRINTS; PR00750; BETAAMYLASE.
DR   PRINTS; PR00841; GLHYDLASE14A.
DR   SUPFAM; SSF51445; SSF51445; 1.
DR   PROSITE; PS00506; BETA_AMYLASE_1; 1.
DR   PROSITE; PS00679; BETA_AMYLASE_2; 1.
PE   3: Inferred from homology;
KW   Carbohydrate metabolism; Disulfide bond; Glycosidase; Hydrolase;
KW   Metal-binding; Polysaccharide degradation; Signal.
FT   SIGNAL          1..36
FT                   /evidence="ECO:0000255"
FT   CHAIN           37..>468
FT                   /note="Beta-amylase"
FT                   /id="PRO_0000001455"
FT   ACT_SITE        198
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10050"
FT   ACT_SITE        394
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         76
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         83
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         87
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         116
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         124
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         170
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         314
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         319
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         357
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         395..396
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   BINDING         423
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   DISULFID        118..126
FT                   /evidence="ECO:0000250|UniProtKB:P36924"
FT   NON_TER         468
SQ   SEQUENCE   468 AA;  51118 MW;  4B0C11D7FD7316AF CRC64;
     MTLYRSLWKK GCMLLLSLVL SLTAFIGSPS NTASAAVADD IQASVMGPLA KINDWGSFKK
     QLQTLKNNGV YAITTDVWWG YVESAGDNQF DWSYYKTYAD AVKEAGLKWV PIISTHKCGG
     NVGDDCNIPL PSWLSSKGSA DEMQFKDESG YANNEALSPL WSGTGKQYDE LYASFAQNFA
     GYKSIIPKIY LSGGPSGELR YPSYYPAAGW SYPGRGKFQA YTETAKNAFR TAMNDKYGSL
     DKINTAWGTK LTSLSQINPP TDGDGFYTNG GYNSAYGKDF LSWYQSVLEK HLGVIGAAAH
     KNFDSVFGVR IGAKISGLHW QMNNPAMPHS TEQAGGYYDY NRLIQKFKDA DLDLTFTCLE
     MSDSGTAPNY SLPSTLVDTV SSIANAKGVR LNGENALQTG GSGFQKIEEK ITKFGYHGFT
     LLRINNLVNN DGSPTGELSG FKQYIISKAK PDNNGGTGNK VTIYYKKG