AMY6_HORVU
ID AMY6_HORVU Reviewed; 429 AA.
AC P04750;
DT 13-AUG-1987, integrated into UniProtKB/Swiss-Prot.
DT 01-NOV-1990, sequence version 2.
DT 03-AUG-2022, entry version 120.
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=Clones GRAMY56 and 963;
DE Flags: Precursor;
GN Name=AMY1.6;
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] (CLONE GRAMY56).
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 [MRNA] OF 380-429 (CLONE 963).
RX PubMed=6335720;
RA Huang J.-K., Swegle M., Dandekar A.M., Muthukrishnan S.;
RT "Expression and regulation of alpha-amylase gene family in barley
RT aleurones.";
RL J. Mol. Appl. Genet. 2:579-588(1984).
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:0000250|UniProtKB:P00693};
CC Note=Binds 3 Ca(2+) ions per subunit. {ECO:0000250|UniProtKB:P00693};
CC -!- SUBUNIT: Monomer. {ECO:0000250}.
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 -!- MISCELLANEOUS: There are at least 4 types of alpha-amylase in barley.
CC -!- MISCELLANEOUS: Type B isozyme mRNA is undetectable in unstimulated
CC cells and increases a hundred-fold after stimulation with gibberellic
CC acid.
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. {ECO:0000250}.
CC -!- SIMILARITY: Belongs to the glycosyl hydrolase 13 family. {ECO:0000305}.
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DR EMBL; X15227; CAA33299.1; -; Genomic_DNA.
DR EMBL; K02636; AAA32932.1; -; mRNA.
DR PIR; JE0406; JE0406.
DR AlphaFoldDB; P04750; -.
DR SMR; P04750; -.
DR IntAct; P04750; 1.
DR CAZy; GH13; Glycoside Hydrolase Family 13.
DR ExpressionAtlas; P04750; baseline and differential.
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 Gene3D; 2.60.40.1180; -; 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 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; SSF51445; 1.
PE 2: Evidence at transcript level;
KW Calcium; Carbohydrate metabolism; Germination; Glycosidase; Hydrolase;
KW Metal-binding; Signal.
FT SIGNAL 1..24
FT CHAIN 25..429
FT /note="Alpha-amylase type B isozyme"
FT /id="PRO_0000001407"
FT ACT_SITE 205
FT /note="Nucleophile"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT ACT_SITE 230
FT /note="Proton donor"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 68..70
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 75..76
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 115
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 132
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 135
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 137
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 141
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="2"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 151
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="3"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 167
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 168
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="3"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 169
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="3"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 172
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="3"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 174
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 174
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="3"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 203..208
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 209
FT /ligand="Ca(2+)"
FT /ligand_id="ChEBI:CHEBI:29108"
FT /ligand_label="1"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 232
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 234
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P04063"
FT BINDING 252
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 295
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 301..303
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 314
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 320
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 399
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 404..406
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 416..422
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT BINDING 426
FT /ligand="substrate"
FT /evidence="ECO:0000250|UniProtKB:P00693"
FT SITE 315
FT /note="Transition state stabilizer"
FT /evidence="ECO:0000250|UniProtKB:P00693"
SQ SEQUENCE 429 AA; 47937 MW; 1C924CA6319D5262 CRC64;
MANKHMSLSL FIVLLGLSCS LASGQVLFQG FNWESWKHNG GWYNFLMGKV DDIAAAGVTH
VWLPPASQSV AEQGYMPGRL YDLDASKYGN KAQLKSLIGA LHGKAVKAIA DIVINHRTAE
RKDGRGIYCI FEGGTPDARL DWGPHMICRD DRPYPDGTGN RPTRTRADFG AAPDIDHLNP
RVQKELVEWL NWLRTDDGFD GWRFDFAKGY SADVAKIYVD RSEPSFAVAE IWTSLAYGGD
GKPNLNQDPH RQELVNWVNK VGGSGPATTF DFTTKGILNV AVEGELWRLR GTDGKAPGMI
GWWPAKAVTF VDNHDTGSTQ HMWPFPSDRV MQGYAYILTH PGNPCIFYDH FFDWGLKEEI
DRLVSIRTRQ GIHSESKLQI MEADADLYLA EIEGKVIVKL GPRYDVGHLI PEGFKVVAHG
NDYAVWEKV
