ID   EABF_STRLI              Reviewed;         475 AA.
AC   P96463;
DT   15-DEC-1998, integrated into UniProtKB/Swiss-Prot.
DT   15-DEC-1998, sequence version 2.
DT   02-SEP-2026, entry version 108.
DE   RecName: Full=Extracellular exo-alpha-L-arabinofuranosidase;
DE            Short=ABF;
DE            EC=3.2.1.55;
DE   AltName: Full=Arabinosidase;
DE   AltName: Full=Arabinoxylan arabinofuranohydrolase;
DE   Flags: Precursor;
GN   Name=abfB;
OS   Streptomyces lividans.
OC   Bacteria; Bacillati; Actinomycetota; Actinomycetes; Kitasatosporales;
OC   Streptomycetaceae; Streptomyces.
OX   NCBI_TaxID=1916;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], FUNCTION, CATALYTIC ACTIVITY,
RP   BIOPHYSICOCHEMICAL PROPERTIES, SUBCELLULAR LOCATION, AND SUBSTRATE
RP   SPECIFICITY.
RC   STRAIN=66 / 1326;
RX   PubMed=9148759; DOI=10.1042/bj3220845;
RA   Vincent P., Shareck F., Dupont C., Morosoli R., Kluepfel D.;
RT   "New alpha-L-arabinofuranosidase produced by Streptomyces lividans: cloning
RT   and DNA sequence of the abfB gene and characterization of the enzyme.";
RL   Biochem. J. 322:845-852(1997).
RN   [2]
RP   SEQUENCE REVISION.
RA   Shareck F.;
RL   Submitted (JUL-1998) to the EMBL/GenBank/DDBJ databases.
CC   -!- FUNCTION: Involved in the degradation of xylan and is a key enzyme in
CC       the complete degradation of the plant cell wall. It has a specific
CC       arabinofuranose-debranching activity on xylan from gramineae. Acts
CC       synergistically with the xylanases and binds specifically to xylan.
CC       From small arabinoxylo-oligosides (ranging from arabinoxylotriose to
CC       arabinoxylohexaose), it liberates arabinose and, after prolonged
CC       incubation, the purified enzyme exhibits some xylanolytic activity as
CC       well. {ECO:0000269|PubMed:9148759}.
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:9148759};
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=1.17 mM for wheat arabinoxylan (at 55 degrees Celsius)
CC         {ECO:0000269|PubMed:9148759};
CC         KM=5.12 mM for oat xylan (at 55 degrees Celsius)
CC         {ECO:0000269|PubMed:9148759};
CC         Vmax=17.2 umol/min/mg enzyme with oat xylan as substrate (at 55
CC         degrees Celsius) {ECO:0000269|PubMed:9148759};
CC         Vmax=18.5 umol/min/mg enzyme with wheat arabinoxylan as substrate (at
CC         55 degrees Celsius) {ECO:0000269|PubMed:9148759};
CC       pH dependence:
CC         Optimum pH is 6. {ECO:0000269|PubMed:9148759};
CC       Temperature dependence:
CC         Optimum temperature is 55 degrees Celsius.
CC         {ECO:0000269|PubMed:9148759};
CC   -!- PATHWAY: Glycan degradation; xylan degradation.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:9148759}.
CC   -!- MISCELLANEOUS: These dual activities might be explained by a rotation
CC       about the alpha-(1->3)-glycosidic bond of the arabinofuranose group to
CC       the xylose moiety of xylan, which produces a bond conformation
CC       resembling that of a beta-(1->4) bond found in xylosides. Thus a single
CC       catalytic site could perform the double activity (PubMed:9148759).
CC       {ECO:0000305|PubMed:9148759}.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 62 family. {ECO:0000305}.
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DR   EMBL; M64551; AAC26524.1; -; Genomic_DNA.
DR   AlphaFoldDB; P96463; -.
DR   SMR; P96463; -.
DR   CAZy; CBM13; Carbohydrate-Binding Module Family 13.
DR   CAZy; GH62; Glycoside Hydrolase Family 62.
DR   UniPathway; UPA00114; -.
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:0046373; P:L-arabinose metabolic process; IEA:InterPro.
DR   GO; GO:0045493; P:xylan catabolic process; IEA:UniProtKB-UniPathway.
DR   CDD; cd23418; beta-trefoil_Ricin_XLN-like; 1.
DR   CDD; cd08987; GH62; 1.
DR   Gene3D; 2.80.10.50; -; 1.
DR   Gene3D; 2.115.10.20; Glycosyl hydrolase domain, family 43; 1.
DR   InterPro; IPR005193; GH62_arabinosidase.
DR   InterPro; IPR023296; Glyco_hydro_beta-prop_sf.
DR   InterPro; IPR035992; Ricin_B-like_lectins.
DR   InterPro; IPR000772; Ricin_B_lectin.
DR   PANTHER; PTHR40631; ALPHA-L-ARABINOFURANOSIDASE AXHA-2-RELATED; 1.
DR   PANTHER; PTHR40631:SF1; ALPHA-L-ARABINOFURANOSIDASE AXHA-2-RELATED; 1.
DR   Pfam; PF03664; Glyco_hydro_62; 1.
DR   Pfam; PF00652; Ricin_B_lectin; 1.
DR   SMART; SM00458; RICIN; 1.
DR   SUPFAM; SSF75005; Arabinanase/levansucrase/invertase; 1.
DR   SUPFAM; SSF50370; Ricin B-like lectins; 1.
DR   PROSITE; PS50231; RICIN_B_LECTIN; 1.
PE   1: Evidence at protein level;
KW   Carbohydrate metabolism; Glycosidase; Hydrolase; Lectin;
KW   Polysaccharide degradation; Secreted; Signal; Xylan degradation.
FT   SIGNAL          1..37
FT                   /evidence="ECO:0000255"
FT   CHAIN           38..475
FT                   /note="Extracellular exo-alpha-L-arabinofuranosidase"
FT                   /id="PRO_0000008037"
FT   DOMAIN          39..166
FT                   /note="Ricin B-type lectin"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00174"
SQ   SEQUENCE   475 AA;  50369 MW;  C3CB14EE7BF85AAD CRC64;
     MHRGSLSRGQ HVRGTRRRGA ALAALAALLV ATAPAQAAGS GALRGAGSNR CLDVLGGSQD
     DGALLQLYDC WGGTNQQWTS TDTGRLTVYG DKCLDVPGHA TAPGTRVQIW SCSGGRNQQW
     RVNSDGTVVG VESGLCLEAA GAGTPNGTAV QLWTCNGGGN QKWTGLTGTP PTDGTCALPS
     TYRWSSTGVL AQPKSGWVAL KDFTTVTHNG RHLVYGSTSS GSSYGSMVFS PFTNWSDMAS
     AGQNAMNQAA VAPTLFYFAP KNIWVLAYQW GSWPFIYRTS SDPTDPNGWS APQPLFTGSI
     SGSDTGPIDQ TLIADGQNMY LFFAGDNGKI YRASMPIGNF PGNFGSSYTT IMSDTKANLF
     EGVQVYKVQG QNQYLMIVEA MGANGRYFRS FTASSLSGSW TPQAASEGNP FAGKANSGAT
     WTNDISHGDL VRDNPDQTMT VDPCNLQFLY QGKAPNAGGH YNSLPWRPGV LTLRH
//