ID   XYNB_CALSA              Reviewed;         488 AA.
AC   P23552;
DT   01-NOV-1991, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1991, sequence version 1.
DT   25-MAY-2022, entry version 84.
DE   RecName: Full=Beta-xylosidase;
DE            EC=3.2.1.37;
DE   AltName: Full=1,4-beta-D-xylan xylohydrolase;
DE   AltName: Full=Xylan 1,4-beta-xylosidase;
GN   Name=xynB;
OS   Caldicellulosiruptor saccharolyticus (Caldocellum saccharolyticum).
OC   Bacteria; Firmicutes; Clostridia; Thermoanaerobacterales;
OC   Thermoanaerobacterales Family III. Incertae Sedis; Caldicellulosiruptor.
OX   NCBI_TaxID=44001;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=2111111; DOI=10.1128/aem.56.4.1017-1024.1990;
RA   Luethi E., Love D.R., McAnulty J., Wallace C., Caughey P.A., Saul D.J.,
RA   Bergquist P.L.;
RT   "Cloning, sequence analysis, and expression of genes encoding xylan-
RT   degrading enzymes from the thermophile 'Caldocellum saccharolyticum'.";
RL   Appl. Environ. Microbiol. 56:1017-1024(1990).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RA   Te'O V.S. Jr., Gibbs M.D., Saul D.J., Bergquist P.L.;
RT   "A cluster of genes involved in xylan degradation cloned from the extreme
RT   thermophile Caldicellulosiruptor saccharolyticus.";
RL   Submitted (MAY-1997) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Beta-xylosidase is an intracellular xylan-degrading enzyme.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of (1->4)-beta-D-xylans, to remove successive D-
CC         xylose residues from the non-reducing termini.; EC=3.2.1.37;
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 39 family. {ECO:0000305}.
CC   -!- CAUTION: It is uncertain whether Met-1 or Met-7 is the initiator.
CC       {ECO:0000305}.
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DR   EMBL; M34459; AAA23063.1; -; Genomic_DNA.
DR   EMBL; AF005383; AAB87376.1; -; Genomic_DNA.
DR   PIR; T30914; T30914.
DR   AlphaFoldDB; P23552; -.
DR   SMR; P23552; -.
DR   CAZy; GH39; Glycoside Hydrolase Family 39.
DR   BRENDA; 3.2.1.37; 1055.
DR   GO; GO:0009044; F:xylan 1,4-beta-xylosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0045493; P:xylan catabolic process; IEA:UniProtKB-KW.
DR   InterPro; IPR000514; Glyco_hydro_39.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   Pfam; PF01229; Glyco_hydro_39; 1.
DR   PRINTS; PR00745; GLHYDRLASE39.
DR   SUPFAM; SSF51445; SSF51445; 1.
DR   PROSITE; PS01027; GLYCOSYL_HYDROL_F39; 1.
PE   3: Inferred from homology;
KW   Carbohydrate metabolism; Glycosidase; Hydrolase;
KW   Polysaccharide degradation; Xylan degradation.
FT   CHAIN           1..488
FT                   /note="Beta-xylosidase"
FT                   /id="PRO_0000057688"
FT   ACT_SITE        163
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU10068"
FT   ACT_SITE        275
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   488 AA;  56366 MW;  7B8801B1B26F4640 CRC64;
     MERRKIMKIT INYGKRLGKI NKFWAKCVGS CHATTALRED WRKQLKKCRD ELGFEYIRFH
     GWLNDDMSVC FRNDDGLLSF SFFNIDSIID FLLEIGMKPF IELSFMPEAL ASGTKTVFHY
     KGNITPPKSY EEWGQLIEEL ARHLISRYGK NEVREWFFEV WNEPNLKDFF WAGTMEEYFK
     LYKYAAFAIK KVDSELRVGG PATAIDAWIP ELKDFCTKNG VPIDFISTHQ YPTDLAFSTS
     SNMEEAMAKA KRGELAERVK KALEEAYPLP VYYTEWNNSP SPRDPYHDIP YDAAFIVKTI
     IDIIDLPLGC YSYWTFTDIF EECGQSSLPF HGGFGLLNIH GIPKPSYRAF QILDKLNGER
     IEIEFEDKSP TIDCIAVQNE REIILVISNH NVPLSPIDTE NIKVVLKGIE NCREVFVERI
     DEYNANPKRV WLEMGSPAYL NREQIEELIK ASELKKEKVS WGIVNNNEIT FDLSVLPHSV
     VAVTIKNG