ID AMY2_HORVU Reviewed; 427 AA. AC P04063; DT 01-NOV-1986, integrated into UniProtKB/Swiss-Prot. DT 15-JUL-1998, sequence version 3. DT 22-FEB-2023, entry version 140. DE RecName: Full=Alpha-amylase type B isozyme; DE EC=3.2.1.1 {ECO:0000250|UniProtKB:P00693}; DE AltName: Full=1,4-alpha-D-glucan glucanohydrolase; DE AltName: Full=AMY2-2; DE AltName: Full=High pI alpha-amylase; DE Flags: Precursor; GN Name=AMY1.2; OS Hordeum vulgare (Barley). OC Eukaryota; Viridiplantae; Streptophyta; Embryophyta; Tracheophyta; OC Spermatophyta; Magnoliopsida; Liliopsida; Poales; Poaceae; BOP clade; OC Pooideae; Triticodae; Triticeae; Hordeinae; Hordeum. OX NCBI_TaxID=4513; RN [1] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RA Rahmatullah R.J., Huang J.K., Clark K.L., Reeck G.R., Chandra G.R., RA Muthukrishnan S.; RT "Nucleotide and predicted amino acid sequences of two different genes for RT high-pI alpha-amylases from barley."; RL Plant Mol. Biol. 12:119-121(1989). RN [2] RP NUCLEOTIDE SEQUENCE [GENOMIC DNA]. RX PubMed=3871776; DOI=10.1016/s0021-9258(19)83685-2; RA Rogers J.C.; RT "Two barley alpha-amylase gene families are regulated differently in RT aleurone cells."; RL J. Biol. Chem. 260:3731-3738(1985). RN [3] RP X-RAY CRYSTALLOGRAPHY (2.80 ANGSTROMS) OF 25-427 IN COMPLEX WITH CALCIUM, RP AND COFACTOR. RX PubMed=8196040; DOI=10.1006/jmbi.1994.1354; RA Kadziola A., Abe J.-I., Svensson B., Haser R.; RT "Crystal and molecular structure of barley alpha-amylase."; RL J. Mol. Biol. 239:104-121(1994). RN [4] RP X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS) OF 25-427 IN COMPLEX WITH CALCIUM RP IONS AND ACARBOSE, ACTIVE SITE, AND COFACTOR. RX PubMed=9571044; DOI=10.1006/jmbi.1998.1683; RA Kadziola A., Sogaard M., Svensson B., Haser R.; RT "Molecular structure of a barley alpha-amylase-inhibitor complex: RT implications for starch binding and catalysis."; RL J. Mol. Biol. 278:205-217(1998). RN [5] RP X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) OF COMPLEX WITH BASI AND CALCIUM RP IONS, AND COFACTOR. RC STRAIN=cv. Menuet; RX PubMed=9634702; DOI=10.1016/s0969-2126(98)00066-5; RA Vallee F., Kadziola A., Bourne Y., Juy M., Rodenburg K.W., Svensson B., RA Haser R.; RT "Barley alpha-amylase bound to its endogenous protein inhibitor BASI: RT crystal structure of the complex at 1.9-A resolution."; RL Structure 6:649-659(1998). 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; Evidence={ECO:0000250|UniProtKB:P00693}; CC -!- COFACTOR: CC Name=Ca(2+); Xref=ChEBI:CHEBI:29108; CC Evidence={ECO:0000269|PubMed:8196040, ECO:0000269|PubMed:9571044, CC ECO:0000269|PubMed:9634702}; CC Note=Binds 3 Ca(2+) ions per subunit. {ECO:0000269|PubMed:8196040, CC ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702}; CC -!- SUBUNIT: Monomer. {ECO:0000269|PubMed:8196040, CC ECO:0000269|PubMed:9571044}. CC -!- DEVELOPMENTAL STAGE: Production of alpha-amylase is hormonally CC regulated. Germinating embryos produce the hormone gibberellic acid, CC which within 10 hours stimulates the aleurone cells covering the CC endosperm of the seed to produce alpha-amylase. The enzyme then CC degrades the starch within the endosperm for use by the developing CC plant embryo. CC -!- INDUCTION: Type B isozyme mRNA is undetectable in unstimulated cells CC and increases a hundred-fold after stimulation with gibberellic acid. CC -!- MISCELLANEOUS: There are at least 4 types of alpha-amylase in barley. CC -!- MISCELLANEOUS: Binds starch not only at the active site, but also via CC accessory binding sites on the protein surface that are important for CC efficient binding to starch granules and thereby increase enzyme CC activity. CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 13 family. {ECO:0000305}. CC --------------------------------------------------------------------------- CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms CC Distributed under the Creative Commons Attribution (CC BY 4.0) License CC --------------------------------------------------------------------------- DR EMBL; X15226; CAA33298.1; -; Genomic_DNA. DR EMBL; K02637; AAA98790.1; -; Genomic_DNA. DR PIR; A31960; ALBHB. DR PDB; 1AMY; X-ray; 2.80 A; A=25-427. DR PDB; 1AVA; X-ray; 1.90 A; A/B=25-427. DR PDB; 1BG9; X-ray; 2.80 A; A=25-427. DR PDBsum; 1AMY; -. DR PDBsum; 1AVA; -. DR PDBsum; 1BG9; -. DR AlphaFoldDB; P04063; -. DR SMR; P04063; -. DR DIP; DIP-6097N; -. DR IntAct; P04063; 1. DR CAZy; GH13; Glycoside Hydrolase Family 13. DR EnsemblPlants; HORVU.MOREX.r2.6HG0512110.1; HORVU.MOREX.r2.6HG0512110.1; HORVU.MOREX.r2.6HG0512110. DR Gramene; HORVU.MOREX.r2.6HG0512110.1; HORVU.MOREX.r2.6HG0512110.1; HORVU.MOREX.r2.6HG0512110. DR BRENDA; 3.2.1.1; 2687. DR EvolutionaryTrace; P04063; -. DR ExpressionAtlas; P04063; baseline. DR GO; GO:0004556; F:alpha-amylase activity; IEA:UniProtKB-EC. DR GO; GO:0005509; F:calcium ion binding; IEA:InterPro. DR GO; GO:0005983; P:starch catabolic process; IEA:UniProt. DR CDD; cd11314; AmyAc_arch_bac_plant_AmyA; 1. DR Gene3D; 3.20.20.80; Glycosidases; 1. DR Gene3D; 2.60.40.1180; Golgi alpha-mannosidase II; 1. DR InterPro; IPR012850; A-amylase_bs_C. DR InterPro; IPR013775; A-amylase_pln. DR InterPro; IPR006046; Alpha_amylase. DR InterPro; IPR006047; Glyco_hydro_13_cat_dom. DR InterPro; IPR013780; Glyco_hydro_b. DR InterPro; IPR017853; Glycoside_hydrolase_SF. DR PANTHER; PTHR43447; ALPHA-AMYLASE; 1. DR PANTHER; PTHR43447:SF11; ALPHA-AMYLASE; 1. DR Pfam; PF07821; Alpha-amyl_C2; 1. DR Pfam; PF00128; Alpha-amylase; 1. DR PIRSF; PIRSF001028; Alph-amls_plant; 1. DR PRINTS; PR00110; ALPHAAMYLASE. DR SMART; SM00642; Aamy; 1. DR SMART; SM00810; Alpha-amyl_C2; 1. DR SUPFAM; SSF51445; (Trans)glycosidases; 1. DR SUPFAM; SSF51011; Glycosyl hydrolase domain; 1. PE 1: Evidence at protein level; KW 3D-structure; Calcium; Carbohydrate metabolism; Germination; Glycosidase; KW Hydrolase; Metal-binding; Signal. FT SIGNAL 1..24 FT CHAIN 25..427 FT /note="Alpha-amylase type B isozyme" FT /id="PRO_0000001405" FT ACT_SITE 203 FT /note="Nucleophile" FT /evidence="ECO:0000305|PubMed:9571044" FT ACT_SITE 228 FT /note="Proton donor" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 75..76 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 115 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 132 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 135 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 137 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 141 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="2" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 151 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 162 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 165 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 166 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 167 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 170 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 172 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 172 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="3" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 201..206 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 207 FT /ligand="Ca(2+)" FT /ligand_id="ChEBI:CHEBI:29108" FT /ligand_label="1" FT /evidence="ECO:0000269|PubMed:8196040, FT ECO:0000269|PubMed:9571044, ECO:0000269|PubMed:9634702, FT ECO:0007744|PDB:1AVA" FT BINDING 230 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 232 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 250 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 257 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 293 FT /ligand="substrate" FT /evidence="ECO:0000250|UniProtKB:P00693" FT BINDING 299..301 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 312 FT /ligand="substrate" FT /evidence="ECO:0000305|PubMed:9571044" FT BINDING 318 FT /ligand="substrate" FT /evidence="ECO:0000250|UniProtKB:P00693" FT BINDING 397 FT /ligand="substrate" FT /evidence="ECO:0000250|UniProtKB:P00693" FT BINDING 414..420 FT /ligand="substrate" FT /evidence="ECO:0000250|UniProtKB:P00693" FT BINDING 424 FT /ligand="substrate" FT /evidence="ECO:0000250|UniProtKB:P00693" FT SITE 313 FT /note="Transition state stabilizer" FT /evidence="ECO:0000305|PubMed:9571044" FT CONFLICT 134 FT /note="G -> D (in Ref. 1; CAA33298)" FT /evidence="ECO:0000305" FT CONFLICT 425 FT /note="E -> Q (in Ref. 1; CAA33298)" FT /evidence="ECO:0000305" FT STRAND 27..29 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 35..37 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 42..47 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 50..56 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 60..63 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 69..71 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 74..77 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 83..85 FT /evidence="ECO:0007829|PDB:1AMY" FT HELIX 91..104 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 107..112 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 120..122 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 128..130 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 134..138 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 144..146 FT /evidence="ECO:0007829|PDB:1AVA" FT TURN 152..154 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 163..165 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 168..170 FT /evidence="ECO:0007829|PDB:1AMY" FT HELIX 178..193 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 199..202 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 205..207 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 210..220 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 223..227 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 239..241 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 246..260 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 263..268 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 270..279 FT /evidence="ECO:0007829|PDB:1AVA" FT TURN 280..282 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 284..287 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 297..299 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 302..304 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 305..309 FT /evidence="ECO:0007829|PDB:1AVA" FT TURN 312..314 FT /evidence="ECO:0007829|PDB:1AVA" FT TURN 316..318 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 325..327 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 328..337 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 338..345 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 346..350 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 355..367 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 376..382 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 385..390 FT /evidence="ECO:0007829|PDB:1AVA" FT TURN 391..393 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 394..400 FT /evidence="ECO:0007829|PDB:1AVA" FT HELIX 405..407 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 410..418 FT /evidence="ECO:0007829|PDB:1AVA" FT STRAND 421..426 FT /evidence="ECO:0007829|PDB:1AVA" SQ SEQUENCE 427 AA; 47356 MW; 957C0B16621BF748 CRC64; MANKHLSLSL FLVLLGLSAS LASGQVLFQG FNWESWKHNG GWYNFLMGKV DDIAAAGITH VWLPPASQSV AEQGYMPGRL YDLDASKYGN KAQLKSLIGA LHGKGVKAIA DIVINHRTAE HKDGRGIYCI FEGGTPDARL DWGPHMICRD DRPYADGTGN PDTGADFGAA PDIDHLNLRV QKELVEWLNW LKADIGFDGW RFDFAKGYSA DVAKIYIDRS EPSFAVAEIW TSLAYGGDGK PNLNQDQHRQ ELVNWVDKVG GKGPATTFDF TTKGILNVAV EGELWRLRGT DGKAPGMIGW WPAKAVTFVD NHDTGSTQHM WPFPSDRVMQ GYAYILTHPG TPCIFYDHFF DWGLKEEIDR LVSVRTRHGI HNESKLQIIE ADADLYLAEI DGKVIVKLGP RYDVGNLIPG GFKVAAHGND YAVWEKI //