ID   AMY1_ECOLI              Reviewed;         676 AA.
AC   P25718; Q2M7N4;
DT   01-MAY-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1992, sequence version 1.
DT   02-SEP-2026, entry version 185.
DE   RecName: Full=Periplasmic alpha-amylase;
DE            EC=3.2.1.1;
DE   AltName: Full=1,4-alpha-D-glucan glucanohydrolase;
DE   Flags: Precursor;
GN   Name=malS; OrderedLocusNames=b3571, JW3543;
OS   Escherichia coli (strain K12).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=83333;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA], AND PROTEIN SEQUENCE OF 18-43.
RC   STRAIN=K12;
RX   PubMed=1544897; DOI=10.1016/s0021-9258(18)42743-3;
RA   Schneider E., Freundlieb S., Tapio S., Boos W.;
RT   "Molecular characterization of the MalT-dependent periplasmic alpha-amylase
RT   of Escherichia coli encoded by malS.";
RL   J. Biol. Chem. 267:5148-5154(1992).
RN   [2]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=8041620; DOI=10.1093/nar/22.13.2576;
RA   Sofia H.J., Burland V., Daniels D.L., Plunkett G. III, Blattner F.R.;
RT   "Analysis of the Escherichia coli genome. V. DNA sequence of the region
RT   from 76.0 to 81.5 minutes.";
RL   Nucleic Acids Res. 22:2576-2586(1994).
RN   [3]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / MG1655 / ATCC 47076;
RX   PubMed=9278503; DOI=10.1126/science.277.5331.1453;
RA   Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V.,
RA   Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F.,
RA   Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B.,
RA   Shao Y.;
RT   "The complete genome sequence of Escherichia coli K-12.";
RL   Science 277:1453-1462(1997).
RN   [4]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=K12 / W3110 / ATCC 27325 / DSM 5911;
RX   PubMed=16738553; DOI=10.1038/msb4100049;
RA   Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S.,
RA   Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.;
RT   "Highly accurate genome sequences of Escherichia coli K-12 strains MG1655
RT   and W3110.";
RL   Mol. Syst. Biol. 2:E1-E5(2006).
RN   [5]
RP   DISULFIDE BONDS.
RX   PubMed=9268356; DOI=10.1074/jbc.272.35.22125;
RA   Spiess C., Happersberger H.P., Glocker M.O., Spiess E., Rippe K.,
RA   Ehrmann M.;
RT   "Biochemical characterization and mass spectrometric disulfide bond mapping
RT   of periplasmic alpha-amylase MalS of Escherichia coli.";
RL   J. Biol. Chem. 272:22125-22133(1997).
CC   -!- FUNCTION: Since only maltooligosaccharides up to a chain length of 6
CC       glucose units are actively transported through the cytoplasmic membrane
CC       via the membrane-bound complex of three proteins, MalF, MalG, and MalK,
CC       longer maltooligosaccharides must first be degraded by the periplasmic
CC       alpha-amylase, the MalS protein.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=Endohydrolysis of (1->4)-alpha-D-glucosidic linkages in
CC         polysaccharides containing three or more (1->4)-alpha-linked D-
CC         glucose units.; EC=3.2.1.1;
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108; Evidence={ECO:0000250};
CC       Note=Binds 1 Ca(2+) ion per subunit. {ECO:0000250};
CC   -!- SUBUNIT: Monomer.
CC   -!- SUBCELLULAR LOCATION: Periplasm.
CC   -!- INDUCTION: Under the regulatory control of the MalT protein.
CC   -!- SIMILARITY: Belongs to the glycosyl hydrolase 13 family. {ECO:0000305}.
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DR   EMBL; X58994; CAA41740.1; -; Genomic_DNA.
DR   EMBL; U00039; AAB18548.1; -; Genomic_DNA.
DR   EMBL; U00096; AAC76595.1; -; Genomic_DNA.
DR   EMBL; AP009048; BAE77722.1; -; Genomic_DNA.
DR   PIR; S23807; S23807.
DR   RefSeq; NP_418028.1; NC_000913.3.
DR   RefSeq; WP_000761225.1; NZ_CP009789.1.
DR   PDB; 8IM8; X-ray; 2.70 A; A/B/C/D=1-676.
DR   AlphaFoldDB; P25718; -.
DR   SMR; P25718; -.
DR   BioGRID; 4261712; 12.
DR   DIP; DIP-10148N; -.
DR   FunCoup; P25718; 60.
DR   IntAct; P25718; 3.
DR   STRING; 511145.b3571; -.
DR   CAZy; GH13; Glycoside Hydrolase Family 13.
DR   jPOST; P25718; -.
DR   PaxDb; 511145-b3571; -.
DR   EnsemblBacteria; AAC76595; AAC76595; b3571.
DR   GeneID; 948088; -.
DR   KEGG; ecj:JW3543; -.
DR   KEGG; eco:b3571; -.
DR   KEGG; ecoc:C3026_19360; -.
DR   PATRIC; fig|1411691.4.peg.3141; -.
DR   EchoBASE; EB1292; -.
DR   eggNOG; COG0366; Bacteria.
DR   HOGENOM; CLU_022115_1_0_6; -.
DR   InParanoid; P25718; -.
DR   OMA; DKVMVVW; -.
DR   OrthoDB; 9761577at2; -.
DR   PhylomeDB; P25718; -.
DR   BioCyc; EcoCyc:ALPHA-AMYL-PERI-MONOMER; -.
DR   BioCyc; MetaCyc:ALPHA-AMYL-PERI-MONOMER; -.
DR   PRO; PR:P25718; -.
DR   Proteomes; UP000000625; Chromosome.
DR   AbasyAtlas; P25718; -.
DR   GO; GO:0030288; C:outer membrane-bounded periplasmic space; IDA:EcoCyc.
DR   GO; GO:0042597; C:periplasmic space; IDA:EcoliWiki.
DR   GO; GO:0004556; F:alpha-amylase activity; IDA:EcoliWiki.
DR   GO; GO:0005509; F:calcium ion binding; IDA:EcoCyc.
DR   GO; GO:0030980; P:alpha-glucan catabolic process; IMP:EcoCyc.
DR   GO; GO:0009313; P:oligosaccharide catabolic process; IEA:InterPro.
DR   FunFam; 3.20.20.80:FF:000079; Alpha-amylase; 1.
DR   FunFam; 3.20.20.80:FF:000089; Periplasmic alpha-amylase; 1.
DR   Gene3D; 3.20.20.80; Glycosidases; 2.
DR   InterPro; IPR014635; A_amylase_MalS.
DR   InterPro; IPR006047; GH13_cat_dom.
DR   InterPro; IPR017853; GH_hydrolase_sf.
DR   InterPro; IPR062233; MalS_N.
DR   NCBIfam; NF007052; PRK09505.1-2; 1.
DR   NCBIfam; NF007054; PRK09505.1-4; 1.
DR   NCBIfam; NF007059; PRK09505.2-4; 1.
DR   NCBIfam; NF007060; PRK09505.2-5; 1.
DR   PANTHER; PTHR10357; ALPHA-AMYLASE FAMILY MEMBER; 1.
DR   PANTHER; PTHR10357:SF209; PERIPLASMIC ALPHA-AMYLASE; 1.
DR   Pfam; PF00128; Alpha-amylase; 2.
DR   Pfam; PF30434; MalS_N; 1.
DR   PIRSF; PIRSF036917; Alph_amls_MalS; 1.
DR   SMART; SM00642; Aamy; 1.
DR   SUPFAM; SSF51445; (Trans)glycosidases; 1.
DR   PDBsum; 8IM8; -.
PE   1: Evidence at protein level;
KW   3D-structure; Calcium; Carbohydrate metabolism; Direct protein sequencing;
KW   Disulfide bond; Glycosidase; Hydrolase; Metal-binding; Periplasm;
KW   Reference proteome; Signal.
FT   SIGNAL          1..17
FT                   /evidence="ECO:0000269|PubMed:1544897"
FT   CHAIN           18..676
FT                   /note="Periplasmic alpha-amylase"
FT                   /id="PRO_0000001339"
FT   ACT_SITE        460
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250"
FT   ACT_SITE        503
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250"
FT   BINDING         314
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   BINDING         464
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000250"
FT   SITE            565
FT                   /note="Transition state stabilizer"
FT                   /evidence="ECO:0000250"
FT   DISULFID        57..75
FT                   /evidence="ECO:0000269|PubMed:9268356"
FT   DISULFID        121..537
FT                   /evidence="ECO:0000269|PubMed:9268356"
FT   STRAND          129..132
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            134..136
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          142..145
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            146..148
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          151..153
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          155..161
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           162..164
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           165..167
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          170..175
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           181..184
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           186..188
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          190..194
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           196..198
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           204..206
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           209..211
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          220..222
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           228..233
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           235..240
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          245..248
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          252..254
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          259..261
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            262..265
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          267..269
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          276..283
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            285..287
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           290..301
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            302..304
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          306..311
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           316..319
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           321..327
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           337..342
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           347..349
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           360..364
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           370..373
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            379..381
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            396..398
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           419..423
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           437..452
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          456..459
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           462..464
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           467..487
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            489..491
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           496..498
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          499..502
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           513..517
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          520..524
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           527..533
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            534..536
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           538..541
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           542..551
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          556..561
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          564..566
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            571..574
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           575..581
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          583..590
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           593..595
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           608..611
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           612..614
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           616..620
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   TURN            621..623
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           624..639
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   HELIX           642..645
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          646..650
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          654..663
FT                   /evidence="ECO:0007829|PDB:8IM8"
FT   STRAND          666..672
FT                   /evidence="ECO:0007829|PDB:8IM8"
SQ   SEQUENCE   676 AA;  75713 MW;  980110EFA45E011D CRC64;
     MKLAACFLTL LPGFAVAASW TSPGFPAFSE QGTGTFVSHA QLPKGTRPLT LNFDQQCWQP
     ADAIKLNQML SLQPCSNTPP QWRLFRDGEY TLQIDTRSGT PTLMISIQNA AEPVASLVRE
     CPKWDGLPLT VDVSATFPEG AAVRDYYSQQ IAIVKNGQIM LQPAATSNGL LLLERAETDT
     SAPFDWHNAT VYFVLTDRFE NGDPSNDQSY GRHKDGMAEI GTFHGGDLRG LTNKLDYLQQ
     LGVNALWISA PFEQIHGWVG GGTKGDFPHY AYHGYYTQDW TNLDANMGNE ADLRTLVDSA
     HQRGIRILFD VVMNHTGYAT LADMQEYQFG ALYLSGDEVK KSLGERWSDW KPAAGQTWHS
     FNDYINFSDK TGWDKWWGKN WIRTDIGDYD NPGFDDLTMS LAFLPDIKTE STTASGLPVF
     YKNKMDTHAK AIDGYTPRDY LTHWLSQWVR DYGIDGFRVD TAKHVELPAW QQLKTEASAA
     LREWKKANPD KALDDKPFWM TGEAWGHGVM QSDYYRHGFD AMINFDYQEQ AAKAVDCLAQ
     MDTTWQQMAE KLQGFNVLSY LSSHDTRLFR EGGDKAAELL LLAPGAVQIF YGDESSRPFG
     PTGSDPLQGT RSDMNWQDVS GKSAASVAHW QKISQFRARH PAIGAGKQTT LLLKQGYGFV
     REHGDDKVLV VWAGQQ
//