ID   AGLB_THENE              Reviewed;         472 AA.
AC   O86959;
DT   25-JAN-2012, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1998, sequence version 1.
DT   25-MAY-2022, entry version 77.
DE   RecName: Full=Cyclomaltodextrinase;
DE            EC=3.2.1.54;
DE   AltName: Full=Maltodextrin glucosidase;
GN   Name=aglB; Synonyms=malA;
OS   Thermotoga neapolitana.
OC   Bacteria; Thermotogae; Thermotogales; Thermotogaceae; Thermotoga.
OX   NCBI_TaxID=2337;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=Z2706-MC24;
RX   PubMed=14593916;
RA   Berezina O.V., Lunina N.A., Zverlov V.V., Naumoff D.G., Liebl W.,
RA   Velikodvorskaya G.A.;
RT   "Thermotoga neapolitana gene clusters participating in degradation of
RT   starch and maltodextins: molecular structure of the locus.";
RL   Mol. Biol. (Mosk.) 37:801-809(2003).
RN   [2]
RP   FUNCTION, CATALYTIC ACTIVITY, SUBSTRATE SPECIFICITY, ACTIVITY REGULATION,
RP   BIOPHYSICOCHEMICAL PROPERTIES, AND SUBUNIT.
RC   STRAIN=Z2706-MC24;
RX   PubMed=14593917;
RA   Lunina N.A., Berezina O.V., Veith B., Zverlov V.V., Vorob'eva I.P.,
RA   Chekanovskaia L.A., Khromov I.S., Raash G., Libel W., Velikodvorskaia G.A.;
RT   "Thermotoga neopolitina gene cluster, participating in degradation of
RT   starch and maltodextrins: expression of aglB and aglA gene in Escherichia
RT   coli, properties of recombinant enzymes.";
RL   Mol. Biol. (Mosk.) 37:810-819(2003).
CC   -!- FUNCTION: Is able to efficiently hydrolyze alpha-, beta-, and gamma-
CC       cyclomaltodextrins and linear maltooligosaccharides, to glucose and
CC       maltose, by decycling cyclodextrins and liberating glucose from the
CC       reducing end of the molecules. Shows a very weak activity on starch and
CC       pullulan. Cannot hydrolyze maltose or disaccharides with various types
CC       of alpha-links. Is not active against beta-glycosidic bonds of poly-,
CC       oligo-, and disaccharides. {ECO:0000269|PubMed:14593917}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=cyclomaltodextrin + H2O = linear maltodextrin;
CC         Xref=Rhea:RHEA:23980, Rhea:RHEA-COMP:14584, Rhea:RHEA-COMP:14707,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:17623, ChEBI:CHEBI:18398; EC=3.2.1.54;
CC         Evidence={ECO:0000269|PubMed:14593917};
CC   -!- ACTIVITY REGULATION: Addition of 1 mM MnCl(2), NiCl(2), CoCl(2),
CC       ZnCl(2), CuCl(2), or 0.1 mM HgCl(2) inhibits the enzyme activity to 0-
CC       6%. Activity is increased in vitro upon addition of CaCl(2), DTT
CC       (relative activity 147%), KCl (180%), or EDTA (180%), as well as after
CC       heating of the enzyme. Is not inhibited by acarbose, a potent alpha-
CC       amylase and alpha-glucosidase inhibitor; on the contrary, acarbose is
CC       degraded quantitatively by AglB, yielding glucose.
CC       {ECO:0000269|PubMed:14593917}.
CC   -!- BIOPHYSICOCHEMICAL PROPERTIES:
CC       Kinetic parameters:
CC         KM=3.9 mM for beta-cyclodextrin (at 80 degrees Celsius)
CC         {ECO:0000269|PubMed:14593917};
CC         Vmax=66 umol/min/mg enzyme with beta-cyclodextrin as substrate (at 80
CC         degrees Celsius) {ECO:0000269|PubMed:14593917};
CC       pH dependence:
CC         Optimum pH is 6.5 with pNP-alpha-D-maltoside as substrate.
CC         {ECO:0000269|PubMed:14593917};
CC       Temperature dependence:
CC         Optimum temperature is 85 degrees Celsius with pNP-alpha-D-maltoside
CC         as substrate. Remains stable after preincubation for various periods
CC         up to 48 hours at temperatures between 50 and 90 degrees Celsius, pH
CC         6.5. The half-life of the enzyme at 95 degrees Celsius is 2 hours.
CC         {ECO:0000269|PubMed:14593917};
CC   -!- SUBUNIT: Forms a mixture of homotetramers, homooctamers, and larger
CC       homooligomers. {ECO:0000269|PubMed:14593917}.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 13 family. {ECO:0000305}.
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DR   EMBL; AJ009832; CAA08867.1; -; Genomic_DNA.
DR   AlphaFoldDB; O86959; -.
DR   SMR; O86959; -.
DR   CAZy; GH13; Glycoside Hydrolase Family 13.
DR   OMA; TPDWVKH; -.
DR   GO; GO:0047798; F:cyclomaltodextrinase activity; IEA:UniProtKB-EC.
DR   GO; GO:0005975; P:carbohydrate metabolic process; IEA:UniProtKB-KW.
DR   Gene3D; 2.60.40.1180; -; 1.
DR   Gene3D; 3.90.400.10; -; 1.
DR   InterPro; IPR006047; Glyco_hydro_13_cat_dom.
DR   InterPro; IPR013780; Glyco_hydro_b.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   InterPro; IPR045857; O16G_dom_2.
DR   Pfam; PF00128; Alpha-amylase; 1.
DR   SMART; SM00642; Aamy; 1.
DR   SUPFAM; SSF51445; SSF51445; 1.
PE   1: Evidence at protein level;
KW   Carbohydrate metabolism; Glycosidase; Hydrolase.
FT   CHAIN           1..472
FT                   /note="Cyclomaltodextrinase"
FT                   /id="PRO_0000415270"
FT   ACT_SITE        209
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        238
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250"
FT   SITE            297
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   472 AA;  55112 MW;  E0A9AA159700D6C5 CRC64;
     MYPIPSWVYD SVVYQIFPDR FFIGKGKTVE DKKDLYLKRG GTIEKWGVPP RKLPGAQHVK
     VFYGGDLWGI AEKIDYLEEL GVNAVYLTPI FLSDTNHKYD TIDYFKIDPQ FGGKRAFVHL
     LKVLHSRNIK LILDGVFNHV GSQHPWFKKA RKKDPEYVNR FFLYRDRHRS WFDVGSLPEL
     NVEVEEVREY ILKVVQHYLE VGVDGWRLDC GHDLGPLVNL WINMKVKEFS SEKYLVSEIW
     TYPAGWEMVD GLMNYNFRSL VLSYVNGETD SIGTELERAY RETKNIFGCW NMLDSHDTPR
     LATTVPVKDL RKLAIVLQFT YPGVPLVYYG TEIGLTGGED PECRATMEWN REKWDMELFE
     FYKKMIRFRR TDPGLRFGEF ILLKEKPLAF MRKAPHPLQD TIVVVNPEEE KNVVLSLPDG
     KIMNATPLFD IFTGEKFHVD GGVVKVPVGR RSFRILKPID LRVGRYRLYK RV