ID   IABF_STRCX              Reviewed;         328 AA.
AC   P82594;
DT   17-JAN-2003, integrated into UniProtKB/Swiss-Prot.
DT   01-OCT-2000, sequence version 1.
DT   25-MAY-2022, entry version 74.
DE   RecName: Full=Extracellular exo-alpha-(1->5)-L-arabinofuranosidase;
DE            Short=ABF;
DE            EC=3.2.1.55;
DE   AltName: Full=Alpha-L-AFase;
DE   AltName: Full=Extracellular arabinan exo-alpha-(1->5)-L-arabinosidase;
DE            Short=Arabinosidase;
DE   Flags: Precursor;
OS   Streptomyces chartreusis.
OC   Bacteria; Actinobacteria; Streptomycetales; Streptomycetaceae;
OC   Streptomyces.
OX   NCBI_TaxID=1969;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 44-72, FUNCTION,
RP   CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, AND SUBSTRATE
RP   SPECIFICITY.
RC   STRAIN=GS901;
RX   PubMed=10657233; DOI=10.1042/bj3460009;
RA   Matsuo N., Kaneko S., Kuno A., Kobayashi H., Kusakabe I.;
RT   "Purification, characterization and gene cloning of two alpha-L-
RT   arabinofuranosidases from Streptomyces chartreusis GS901.";
RL   Biochem. J. 346:9-15(2000).
CC   -!- FUNCTION: Involved in the degradation of arabinan and is a key enzyme
CC       in the complete degradation of the plant cell wall. Catalyzes only the
CC       cleavage of terminal alpha-(1->5) arabinofuranosyl bonds of arabinan
CC       present in the arabinofuranosyl polysaccharides or oligosaccharides. It
CC       cannot act on other arabinose-containing polysaccharides and
CC       arabinoxylo-oligosaccharides. {ECO:0000269|PubMed:10657233}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of terminal non-reducing alpha-L-arabinofuranoside
CC         residues in alpha-L-arabinosides.; EC=3.2.1.55;
CC         Evidence={ECO:0000269|PubMed:10657233};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       pH dependence:
CC         Optimum pH is 7.0. The enzyme is slowly inactivated above pH 9 and
CC         below pH 5. {ECO:0000269|PubMed:10657233};
CC       Temperature dependence:
CC         Optimum temperature is 50 degrees Celsius. The enzyme is inactivated
CC         at temperatures above 40 degrees Celsius.
CC         {ECO:0000269|PubMed:10657233};
CC   -!- PATHWAY: Glycan metabolism; L-arabinan degradation.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- PTM: Predicted to be exported by the Tat system. The position of the
CC       signal peptide cleavage has been experimentally proven.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 43 family. {ECO:0000305}.
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DR   EMBL; AB023626; BAA90772.1; -; Genomic_DNA.
DR   PIR; B59296; B59296.
DR   AlphaFoldDB; P82594; -.
DR   SMR; P82594; -.
DR   CAZy; GH43; Glycoside Hydrolase Family 43.
DR   UniPathway; UPA00667; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0046556; F:alpha-L-arabinofuranosidase activity; IEA:UniProtKB-EC.
DR   GO; GO:0031222; P:arabinan catabolic process; IEA:UniProtKB-UniPathway.
DR   Gene3D; 2.115.10.20; -; 1.
DR   InterPro; IPR016828; Alpha-L-arabinofuranosidase.
DR   InterPro; IPR006710; Glyco_hydro_43.
DR   InterPro; IPR023296; Glyco_hydro_beta-prop_sf.
DR   InterPro; IPR006311; TAT_signal.
DR   Pfam; PF04616; Glyco_hydro_43; 1.
DR   PIRSF; PIRSF025414; Alpha-L-arabinofuranosidase; 1.
DR   SUPFAM; SSF75005; SSF75005; 1.
DR   PROSITE; PS51318; TAT; 1.
PE   1: Evidence at protein level;
KW   Carbohydrate metabolism; Direct protein sequencing; Glycosidase; Hydrolase;
KW   Secreted; Signal.
FT   SIGNAL          1..43
FT                   /note="Tat-tyPE signal"
FT                   /evidence="ECO:0000269|PubMed:10657233"
FT   CHAIN           44..328
FT                   /note="Extracellular exo-alpha-(1->5)-L-
FT                   arabinofuranosidase"
FT                   /id="PRO_0000012203"
FT   ACT_SITE        60
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250|UniProtKB:Q82P90"
FT   ACT_SITE        236
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:Q82P90"
FT   SITE            175
FT                   /note="Important for catalytic activity, responsible for
FT                   pKa modulation of the active site Glu and correct
FT                   orientation of both the proton donor and substrate"
FT                   /evidence="ECO:0000250|UniProtKB:Q82P90"
SQ   SEQUENCE   328 AA;  36774 MW;  AA7D5C1D2ABF38D5 CRC64;
     MCTREAVRMS REHDLPEIPS RRLLLKGAAA AGALTAVPGV AHAAPRPAPY ENPLVRQRAD
     PHIHRHTDGR YYFTATAPEY DRIVLRRSRT LGGLSTAAES VIWRAHPTGD MAAHIWAPEL
     HRIGGKWYVY FAAAPAEDVW RIRIWVLENS HPDPFKGTWE EKGQVRTAWE TFSLDATTFT
     HRGARYLCWA QHEPGADNNT GLFLSEMANP WTLTGPQIRL STPEYDWECV GYKVNEGPYA
     LKRNGRIFLT YSASATDHHY CVGMFTADAG GNLMDPGNWS KSPIPVFTGN ETTKQYGPGH
     NCFTVAEDGR SDVLVYHARQ YKEIVGDP