ID   AMT4_STUST              Reviewed;         548 AA.
AC   P13507;
DT   01-JAN-1990, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1997, sequence version 2.
DT   27-MAR-2024, entry version 141.
DE   RecName: Full=Glucan 1,4-alpha-maltotetraohydrolase;
DE            Short=G4-amylase;
DE            EC=3.2.1.60 {ECO:0000269|PubMed:10556241, ECO:0000269|PubMed:2646279, ECO:0000269|PubMed:9281429};
DE   AltName: Full=Exo-maltotetraohydrolase;
DE   AltName: Full=Maltotetraose-forming amylase;
DE   AltName: Full=Maltotetraose-forming exo-amylase;
DE   Flags: Precursor;
GN   Name=amyP;
OS   Stutzerimonas stutzeri (Pseudomonas stutzeri).
OC   Bacteria; Pseudomonadota; Gammaproteobacteria; Pseudomonadales;
OC   Pseudomonadaceae; Stutzerimonas.
OX   NCBI_TaxID=316;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], PARTIAL PROTEIN SEQUENCE, AND CATALYTIC
RP   ACTIVITY.
RC   STRAIN=MO-19;
RX   PubMed=2646279; DOI=10.1128/jb.171.3.1333-1339.1989;
RA   Fujita M., Torigoe K., Nakada T., Tsusaki K., Kubota M., Sakai S.,
RA   Tsujisaka Y.;
RT   "Cloning and nucleotide sequence of the gene (amyP) for maltotetraose-
RT   forming amylase from Pseudomonas stutzeri MO-19.";
RL   J. Bacteriol. 171:1333-1339(1989).
RN   [2]
RP   X-RAY CRYSTALLOGRAPHY (2.00 ANGSTROMS) OF 22-439 IN COMPLEX WITH CALCIUM,
RP   SEQUENCE REVISION TO 286-302, DISULFIDE BONDS, AND COFACTOR.
RC   STRAIN=MO-19;
RX   PubMed=9126844; DOI=10.1006/jmbi.1996.0887;
RA   Morishita Y., Hasegawa K., Matsuura Y., Katsube Y., Kubota M., Sakai S.;
RT   "Crystal structure of a maltotetraose-forming exo-amylase from Pseudomonas
RT   stutzeri.";
RL   J. Mol. Biol. 267:661-672(1997).
RN   [3]
RP   X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) OF MUTANT GLN-240 IN COMPLEX WITH
RP   MALTOPENTAOSE AND CALCIUM IONS, DISULFIDE BONDS, MUTAGENESIS OF GLU-240,
RP   CATALYTIC ACTIVITY, AND COFACTOR.
RC   STRAIN=MO-19;
RX   PubMed=9281429; DOI=10.1006/jmbi.1997.1222;
RA   Yoshioka Y., Hasegawa K., Matsuura Y., Katsube Y., Kubota M.;
RT   "Crystal structures of a mutant maltotetraose-forming exo-amylase
RT   cocrystallized with maltopentaose.";
RL   J. Mol. Biol. 271:619-628(1997).
RN   [4]
RP   X-RAY CRYSTALLOGRAPHY (2.00 ANGSTROMS) OF 22-450 IN COMPLEX WITH CALCIUM
RP   AND MALTOTETRAOSE, DISULFIDE BONDS, ACTIVE SITE, MUTAGENESIS OF ASP-214;
RP   GLU-240 AND ASP-315, CATALYTIC ACTIVITY, AND COFACTOR.
RC   STRAIN=MO-19;
RX   PubMed=10556241; DOI=10.1093/protein/12.10.819;
RA   Hasegawa K., Kubota M., Matsuura Y.;
RT   "Roles of catalytic residues in alpha-amylases as evidenced by the
RT   structures of the product-complexed mutants of a maltotetraose-forming
RT   amylase.";
RL   Protein Eng. 12:819-824(1999).
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Hydrolysis of (1->4)-alpha-D-glucosidic linkages in amylaceous
CC         polysaccharides, to remove successive maltotetraose residues from the
CC         non-reducing chain ends.; EC=3.2.1.60;
CC         Evidence={ECO:0000269|PubMed:10556241, ECO:0000269|PubMed:2646279,
CC         ECO:0000269|PubMed:9281429};
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108;
CC         Evidence={ECO:0000269|PubMed:10556241, ECO:0000269|PubMed:9126844,
CC         ECO:0000269|PubMed:9281429};
CC       Note=Binds 2 calcium ions per subunit. {ECO:0000269|PubMed:10556241,
CC       ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429};
CC   -!- PATHWAY: Glycan degradation; starch degradation.
CC       {ECO:0000305|PubMed:10556241, ECO:0000305|PubMed:9281429}.
CC   -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:9281429}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000305|PubMed:2646279}.
CC   -!- MISCELLANEOUS: There are several isoenzyme forms of this protein.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 13 family. {ECO:0000305}.
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DR   EMBL; M24516; AAA25707.1; -; Genomic_DNA.
DR   PIR; A32803; A32803.
DR   PDB; 1GCY; X-ray; 1.60 A; A=22-548.
DR   PDB; 1JDA; X-ray; 2.20 A; A=22-450.
DR   PDB; 1JDC; X-ray; 1.90 A; A=22-450.
DR   PDB; 1JDD; X-ray; 1.90 A; A=22-450.
DR   PDB; 1QI3; X-ray; 2.00 A; A=22-450.
DR   PDB; 1QI4; X-ray; 2.00 A; A=22-450.
DR   PDB; 1QI5; X-ray; 2.00 A; A=22-450.
DR   PDB; 1QPK; X-ray; 2.00 A; A=22-439.
DR   PDB; 2AMG; X-ray; 2.00 A; A=22-439.
DR   PDBsum; 1GCY; -.
DR   PDBsum; 1JDA; -.
DR   PDBsum; 1JDC; -.
DR   PDBsum; 1JDD; -.
DR   PDBsum; 1QI3; -.
DR   PDBsum; 1QI4; -.
DR   PDBsum; 1QI5; -.
DR   PDBsum; 1QPK; -.
DR   PDBsum; 2AMG; -.
DR   AlphaFoldDB; P13507; -.
DR   SMR; P13507; -.
DR   DrugBank; DB02379; Beta-D-Glucose.
DR   DrugBank; DB02237; Maltotetraose.
DR   CAZy; CBM20; Carbohydrate-Binding Module Family 20.
DR   CAZy; GH13; Glycoside Hydrolase Family 13.
DR   UniPathway; UPA00153; -.
DR   EvolutionaryTrace; P13507; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0004556; F:alpha-amylase activity; IEA:InterPro.
DR   GO; GO:0033910; F:glucan 1,4-alpha-maltotetraohydrolase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:2001070; F:starch binding; IEA:InterPro.
DR   GO; GO:0005983; P:starch catabolic process; IEA:UniProtKB-UniPathway.
DR   CDD; cd11314; AmyAc_arch_bac_plant_AmyA; 1.
DR   CDD; cd05810; CBM20_alpha_MTH; 1.
DR   Gene3D; 3.20.20.80; Glycosidases; 1.
DR   Gene3D; 2.60.40.1180; Golgi alpha-mannosidase II; 1.
DR   Gene3D; 2.60.40.10; Immunoglobulins; 1.
DR   InterPro; IPR006046; Alpha_amylase.
DR   InterPro; IPR015165; AMT4_domain_C.
DR   InterPro; IPR013784; Carb-bd-like_fold.
DR   InterPro; IPR002044; CBM_fam20.
DR   InterPro; IPR006047; Glyco_hydro_13_cat_dom.
DR   InterPro; IPR013780; Glyco_hydro_b.
DR   InterPro; IPR017853; Glycoside_hydrolase_SF.
DR   InterPro; IPR013783; Ig-like_fold.
DR   PANTHER; PTHR43447; ALPHA-AMYLASE; 1.
DR   PANTHER; PTHR43447:SF49; ALPHA-AMYLASE; 1.
DR   Pfam; PF00128; Alpha-amylase; 1.
DR   Pfam; PF09081; AMT4_dom_C; 1.
DR   Pfam; PF00686; CBM_20; 1.
DR   PRINTS; PR00110; ALPHAAMYLASE.
DR   SMART; SM00642; Aamy; 1.
DR   SMART; SM01065; CBM_2; 1.
DR   SUPFAM; SSF51445; (Trans)glycosidases; 1.
DR   SUPFAM; SSF51011; Glycosyl hydrolase domain; 1.
DR   SUPFAM; SSF49452; Starch-binding domain-like; 1.
DR   PROSITE; PS51166; CBM20; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Calcium; Carbohydrate metabolism; Direct protein sequencing;
KW   Disulfide bond; Glycosidase; Hydrolase; Metal-binding; Secreted; Signal.
FT   SIGNAL          1..21
FT   CHAIN           22..548
FT                   /note="Glucan 1,4-alpha-maltotetraohydrolase"
FT                   /id="PRO_0000001420"
FT   DOMAIN          446..548
FT                   /note="CBM20"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU00594"
FT   REGION          529..548
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   ACT_SITE        214
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000305|PubMed:10556241"
FT   ACT_SITE        240
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000305|PubMed:10556241,
FT                   ECO:0000305|PubMed:9281429"
FT   BINDING         22
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         23
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         34
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         37
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         38
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="1"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         99..100
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000305|PubMed:10556241"
FT   BINDING         137
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         138
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000305|PubMed:10556241,
FT                   ECO:0000305|PubMed:9281429"
FT   BINDING         172
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         175
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         177..181
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000305|PubMed:10556241"
FT   BINDING         183
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         212
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000305|PubMed:10556241,
FT                   ECO:0000305|PubMed:9281429"
FT   BINDING         217..218
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P0C1B3"
FT   BINDING         218
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /ligand_label="2"
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   BINDING         314
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000305|PubMed:10556241,
FT                   ECO:0000305|PubMed:9281429"
FT   BINDING         326
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000305|PubMed:10556241"
FT   SITE            315
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000305|PubMed:10556241"
FT   DISULFID        161..171
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   DISULFID        237..272
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9126844, ECO:0000269|PubMed:9281429"
FT   MUTAGEN         214
FT                   /note="D->N: Abolishes enzyme activity."
FT                   /evidence="ECO:0000269|PubMed:10556241"
FT   MUTAGEN         240
FT                   /note="E->Q: Abolishes enzyme activity."
FT                   /evidence="ECO:0000269|PubMed:10556241,
FT                   ECO:0000269|PubMed:9281429"
FT   MUTAGEN         315
FT                   /note="D->N: Abolishes enzyme activity."
FT                   /evidence="ECO:0000269|PubMed:10556241"
FT   CONFLICT        286..302
FT                   /note="GSIADWKHGLNGNPDPR -> ARSPTGSTPERQSRPA (in Ref. 1; AA
FT                   sequence)"
FT                   /evidence="ECO:0000305"
FT   HELIX           34..36
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          40..42
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           48..51
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   TURN            53..55
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           56..69
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          73..77
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          87..89
FT                   /evidence="ECO:0007829|PDB:1JDC"
FT   STRAND          92..94
FT                   /evidence="ECO:0007829|PDB:1JDC"
FT   STRAND          102..104
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          108..110
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           113..125
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          129..134
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          152..155
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           158..160
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          165..167
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          172..174
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          180..184
FT                   /evidence="ECO:0007829|PDB:1QI5"
FT   HELIX           189..205
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          208..214
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           216..218
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           221..231
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          235..239
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           245..247
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           253..256
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           259..270
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           277..285
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           288..293
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           295..297
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           301..304
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          307..309
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   TURN            314..316
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           322..324
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           333..335
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           336..345
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          346..353
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           354..358
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           363..376
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          383..386
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          390..398
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          403..409
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   HELIX           415..417
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          424..429
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   TURN            430..433
FT                   /evidence="ECO:0007829|PDB:1GCY"
FT   STRAND          434..438
FT                   /evidence="ECO:0007829|PDB:1GCY"
SQ   SEQUENCE   548 AA;  59876 MW;  2B87217B3379158F CRC64;
     MSHILRAAVL AAMLLPLPSM ADQAGKSPNA VRYHGGDEII LQGFHWNVVR EAPNDWYNIL
     RQQAATIAAD GFSAIWMPVP WRDFSSWSDG SKSGGGEGYF WHDFNKNGRY GSDAQLRQAA
     SALGGAGVKV LYDVVPNHMN RGYPDKEINL PAGQGFWRND CADPGNYPND CDDGDRFIGG
     DADLNTGHPQ VYGMFRDEFT NLRSQYGAGG FRFDFVRGYA PERVNSWMTD SADNSFCVGE
     LWKGPSEYPN WDWRNTASWQ QIIKDWSDRA KCPVFDFALK ERMQNGSIAD WKHGLNGNPD
     PRWREVAVTF VDNHDTGYSP GQNGGQHHWA LQDGLIRQAY AYILTSPGTP VVYWSHMYDW
     GYGDFIRQLI QVRRAAGVRA DSAISFHSGY SGLVATVSGS QQTLVVALNS DLGNPGQVAS
     GSFSEAVNAS NGQVRVWRSG TGSGGGEPGA LVSVSFRCDN GATQMGDSVY AVGNVSQLGN
     WSPAAALRLT DTSGYPTWKG SIALPAGQNE EWKCLIRNEA NATQVRQWQG GANNSLTPSE
     GATTVGRL
//