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discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
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Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
Metabolic Modeling Tutorial
discounted EARLY registration ends Dec 31, 2014
BioCyc websites down
12/28 - 12/31
for maintenance.
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MetaCyc Enzyme: α-amylase

Gene: amyA Accession Numbers: EG11387 (MetaCyc), b1927, ECK1926

Synonyms: yedC

Species: Escherichia coli K-12 substr. MG1655

Summary:
AmyA is a cytoplasmic α-amylase. Amylose, a linear α-glucan, is the most effective substrate in vitro; starch and amylopectin, a lightly branched α-glucan, can serve as good substrates, while the highly branched α-glucan glycogen is a poor substrate. Linear oligomeric α-glucans of six or more glucose moieties are good substrates of AmyA [Raha92].

The physiological role of AmyA is uncertain. Although under experimental conditions glycogen is a poor substrate for the enzyme, it is the most likely natural substrate since it is the only polysaccharide present in appreciable amounts in the cytoplasm. It has been hypothesized that in the absence of exogenous oligosaccharides that could act as primers for glycogen synthesis, the cytoplasmic amylase might provide oligosaccharides through catabolism of existing cellular glycogen, which would then act as the source of primers for the synthesis of more molecules of glycogen [Raha92].

AmyA is one of two α-amylases present in E. coli. The second enzyme, MalS, is periplasmic.

Locations: cytosol

Map Position: [2,004,180 -> 2,005,667]

Molecular Weight of Polypeptide: 56.639 kD (from nucleotide sequence), 56 kD (experimental) [Raha92 ]

pI: 4.71

Unification Links: ASAP:ABE-0006414 , CGSC:30745 , DIP:DIP-9108N , EchoBASE:EB1360 , EcoGene:EG11387 , EcoliWiki:b1927 , Mint:MINT-1279253 , ModBase:P26612 , OU-Microarray:b1927 , PortEco:amyA , PR:PRO_000022101 , Pride:P26612 , Protein Model Portal:P26612 , RefSeq:NP_416437 , RegulonDB:EG11387 , SMR:P26612 , String:511145.b1927 , UniProt:P26612

Relationship Links: CAZy:IN-FAMILY:GH13 , InterPro:IN-FAMILY:IPR006047 , InterPro:IN-FAMILY:IPR006589 , InterPro:IN-FAMILY:IPR013776 , InterPro:IN-FAMILY:IPR013780 , InterPro:IN-FAMILY:IPR013781 , InterPro:IN-FAMILY:IPR015902 , InterPro:IN-FAMILY:IPR017853 , Panther:IN-FAMILY:PTHR10357 , Pfam:IN-FAMILY:PF00128 , Smart:IN-FAMILY:SM00642

Gene-Reaction Schematic: ?

GO Terms:

Biological Process: GO:0005975 - carbohydrate metabolic process Inferred by computational analysis [UniProtGOA11a, GOA01a]
GO:0008152 - metabolic process Inferred by computational analysis [UniProtGOA11a]
Molecular Function: GO:0004556 - alpha-amylase activity Inferred from experiment Inferred by computational analysis [GOA01, Raha92]
GO:0003824 - catalytic activity Inferred by computational analysis [GOA01a]
GO:0004553 - hydrolase activity, hydrolyzing O-glycosyl compounds Inferred by computational analysis [GOA01a]
GO:0005509 - calcium ion binding Inferred by computational analysis [GOA01a]
GO:0016787 - hydrolase activity Inferred by computational analysis [UniProtGOA11a]
GO:0016798 - hydrolase activity, acting on glycosyl bonds Inferred by computational analysis [UniProtGOA11a]
GO:0043169 - cation binding Inferred by computational analysis [GOA01a]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0005737 - cytoplasm Inferred from experiment Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, Raha92]
GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09, Raha92]

MultiFun Terms: metabolism carbon utilization carbon compounds
metabolism degradation of macromolecules polysaccharides

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International


Enzymatic reaction of: α-amylase

Synonyms: 1,4-α-D-glucan glucanohydrolase

a 1,4-α-D-glucan + n H2O <=> n a 1,4-α-D-glucan

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction of enzyme catalysis.

The reaction is physiologically favored in the direction shown.

Alternative Substrates [Comment 1]:

Credits:
Imported from EcoCyc 16-Sep-2014 by Paley S , SRI International

Summary:
Various reaction products, such as maltopentaose, maltotetraose, maltotriose, and maltose have been observed [Raha92].

T(opt): 45 °C [Raha92]

pH(opt): 7.2 [Raha92]


Sequence Features

Feature Class Location Citations Comment
Sequence-Conflict 19 -> 20
[Raha92, UniProt10a]
Alternate sequence: SS; UniProt: (in Ref. 1; AAA23810);
Metal-Binding-Site 104
[UniProt10]
UniProt: Calcium; Non-Experimental Qualifier: by similarity;
Sequence-Conflict 109
[Raha92, UniProt10a]
Alternate sequence: V; UniProt: (in Ref. 1; AAA23810);
Sequence-Conflict 149
[Raha92, UniProt10a]
Alternate sequence: E; UniProt: (in Ref. 1; AAA23810);
Sequence-Conflict 234
[Raha92, UniProt10a]
Alternate sequence: I; UniProt: (in Ref. 1; AAA23810);
Active-Site 235
[UniProt10]
UniProt: Nucleophile; Non-Experimental Qualifier: by similarity;
Metal-Binding-Site 239
[UniProt10]
UniProt: Calcium; via carbonyl oxygen; Non-Experimental Qualifier: by similarity;
Active-Site 265
[UniProt10]
UniProt: Proton donor; Non-Experimental Qualifier: by similarity;
Active-Site 332
[UniProt10]
UniProt: Non-Experimental Qualifier: by similarity;

History:
10/20/97 Gene b1927 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG11387; confirmed by SwissProt match.


References

DiazMejia09: Diaz-Mejia JJ, Babu M, Emili A (2009). "Computational and experimental approaches to chart the Escherichia coli cell-envelope-associated proteome and interactome." FEMS Microbiol Rev 33(1);66-97. PMID: 19054114

GOA01: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

GOA01a: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

Raha92: Raha M, Kawagishi I, Muller V, Kihara M, Macnab RM (1992). "Escherichia coli produces a cytoplasmic alpha-amylase, AmyA." J Bacteriol 1992;174(20);6644-52. PMID: 1400215

UniProt10: UniProt Consortium (2010). "UniProt version 2010-07 released on 2010-06-15 00:00:00." Database.

UniProt10a: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 00:00:00." Database.

UniProtGOA11: UniProt-GOA (2011). "Gene Ontology annotation based on the manual assignment of UniProtKB Subcellular Location terms in UniProtKB/Swiss-Prot entries."

UniProtGOA11a: UniProt-GOA (2011). "Gene Ontology annotation based on manual assignment of UniProtKB keywords in UniProtKB/Swiss-Prot entries."


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
Page generated by SRI International Pathway Tools version 18.5 on Sat Dec 20, 2014, BIOCYC13B.