MetaCyc Enzyme: glycogen phosphorylase

Gene: glgP Accession Numbers: EG10380 (MetaCyc), b3428, ECK3414

Synonyms: glgY

Species: Escherichia coli K-12 substr. MG1655

Subunit composition of glycogen phosphorylase = [GlgP]2

The glgP gene product, glycogen phosphorylase, is one of two distinct α-glucan phosphorylases in E. coli. A maltodextrin phosphorylase is encoded by the malP gene, and glycogen phosphorylase is encoded by glgP. The two isozymes are more closely related to each other than to phosphorylases from other organisms [Hudson93a]. GlgP catalyzes a step in the breakdown of glycogen, removing glucose units from the polysaccharide outer chains [AlonsoCasajus06].

Glycogen phosphorylase shows a marked preference for the larger polymer glycogen over the smaller maltodextrins as the polyglucose acceptor, although its affinity even for glycogen is low. It is believed that glycogen phosphorylase plays a role in the slow degradation of endogenous glycogen during long stationary conditions [Chen68a, Chen68, Yu88].

The histidine phosphocarrier protein (HPr) component of the PEP:sugar phosphotransferase system (PTS) binds to glycogen phosphorylase and allosterically regulates the oligomeric state of the enzyme. Binding of HPr to GlgP decreases the Km of GlgP for glycogen 5-fold. Phosphorylated HPr has 4-fold higher affinity for GlgP than the unphosphorylated form, although it does not appear to stimulate the activity of GlgP [Seok97].

ΔglgP mutants display a glycogen-excess phenotype [Eydallin07].

Reviews: [Schinzel99, Seok01]

Locations: cytosol

Map Position: [3,562,157 <- 3,564,604]

Molecular Weight of Polypeptide: 93.172 kD (from nucleotide sequence)

Molecular Weight of Multimer: 200 kD (experimental) [Yu88]

pI: 5.71

Unification Links: ASAP:ABE-0011198 , CGSC:33653 , DIP:DIP-47899N , EchoBASE:EB0375 , EcoGene:EG10380 , EcoliWiki:b3428 , Mint:MINT-1307808 , ModBase:P0AC86 , OU-Microarray:b3428 , PortEco:glgP , PR:PRO_000022778 , Pride:P0AC86 , Protein Model Portal:P0AC86 , RefSeq:NP_417886 , RegulonDB:EG10380 , SMR:P0AC86 , String:511145.b3428 , Swiss-Model:P0AC86 , UniProt:P0AC86

Relationship Links: InterPro:IN-FAMILY:IPR000811 , InterPro:IN-FAMILY:IPR011833 , Panther:IN-FAMILY:PTHR11468 , Pfam:IN-FAMILY:PF00343 , Prosite:IN-FAMILY:PS00102

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

GO Terms:

Biological Process: GO:0005980 - glycogen catabolic process Inferred from experiment [Eydallin07]
GO:0016052 - carbohydrate catabolic process Inferred from experiment [Chen68]
GO:0005975 - carbohydrate metabolic process Inferred by computational analysis [UniProtGOA11, GOA01]
GO:0005977 - glycogen metabolic process Inferred by computational analysis [UniProtGOA11]
GO:0008152 - metabolic process Inferred by computational analysis [UniProtGOA11]
Molecular Function: GO:0008184 - glycogen phosphorylase activity Inferred from experiment Inferred by computational analysis [GOA01, Yu88]
GO:0030170 - pyridoxal phosphate binding Inferred from experiment Inferred by computational analysis [GOA01, Chen68]
GO:0042803 - protein homodimerization activity Inferred from experiment [Yu88]
GO:0003824 - catalytic activity Inferred by computational analysis [UniProtGOA11]
GO:0004645 - phosphorylase activity Inferred by computational analysis [GOA01a, GOA01]
GO:0016740 - transferase activity Inferred by computational analysis [UniProtGOA11]
GO:0016757 - transferase activity, transferring glycosyl groups Inferred by computational analysis [UniProtGOA11]
Cellular Component: GO:0005737 - cytoplasm Inferred by computational analysis [Gaudet10]
GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09]

MultiFun Terms: metabolism biosynthesis of macromolecules (cellular constituents) cytoplasmic polysaccharides
metabolism carbon utilization carbon compounds

Imported from EcoCyc 02-Jun-2015 by Paley S , SRI International

Enzymatic reaction of: glycogen phosphorylase

Synonyms: amylophosphorylase, polyphosphorylase, polyglucose phosphorylase, 1,4-α-D-glucan:orthophosphate α-D-glucosyltransferase

a glycogen + phosphate <=> an α-limit dextrin + α-D-glucopyranose 1-phosphate

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the Enzyme Commission system.

This reaction is reversible.

In Pathways: glycogen degradation I (bacterial)

Imported from EcoCyc 02-Jun-2015 by Paley S , SRI International

The reaction is reversible in vitro. 5'-AMP activates the enzyme in both the phosphorolysis and glycogen synthesis directions [Chen68]. However, another study showed only a 10% increase in glycogen phosphorylase activity by addition of 5'-AMP [Seok97], and when assayed in the glycogen breakdown direction, no regulatory effect by AMP, ADP-glucose, UDP-glucose, glucose, and hexose-phosphates was observed [AlonsoCasajus06].

Cofactors or Prosthetic Groups: pyridoxal 5'-phosphate [Chen68]

Activators (Allosteric): HPr [Seok97]

Activators (Unknown Mechanism): AMP [Yu88, Chen68a, Chen68] , sodium sulfate [Chen68, Chen68a] , fluoride [Chen68, Chen68a]

Inhibitors (Competitive): UDP-D-glucose [Chen68, Comment 1] , β-D-glucopyranose [Chen68, Comment 1] , ADP-α-D-glucose [Chen68, Comment 1] , dTDP-α-D-glucose [Chen68, Comment 1]

Inhibitors (Unknown Mechanism): persulfate [Chen68a, Chen68] , nitrate [Chen68a, Chen68] , iodide [Chen68a, Chen68] , Cu2+ [Chen68a, Chen68] , Zn2+ [Chen68a, Chen68] , Hg2+ [Chen68a, Chen68] , Ag2+ [Chen68a, Chen68] , p-chloromercuribenzoate [Chen68a, Chen68] , hydrogen cyanide [Chen68, Chen68a]

Kinetic Parameters:

Km (μM)
α-D-glucopyranose 1-phosphate
[Chen68, BRENDA14]
α-D-glucopyranose 1-phosphate
[Boeck96, BRENDA14]

pH(opt): 6.7 [BRENDA14, Chen68], 6.7-6.9 [Chen68]

Sequence Features

Feature Class Location Citations Comment
Sequence-Conflict 13 -> 14
[Choi89a, UniProt10a]
UniProt: (in Ref. 1);
Sequence-Conflict 60
[Romeo88, UniProt10a]
UniProt: (in Ref. 5; AAA23875);
Sequence-Conflict 94 -> 95
[Romeo88, UniProt10a]
UniProt: (in Ref. 5; AAA23875);
Sequence-Conflict 142
[Romeo88, UniProt10a]
UniProt: (in Ref. 5; AAA23875);
Sequence-Conflict 175
[Choi89a, UniProt10a]
UniProt: (in Ref. 1; CAA34807);
Sequence-Conflict 182 -> 187
[Yu88, UniProt10a]
UniProt: (in Ref. 2; AAA23874);
Sequence-Conflict 191
[Choi89a, UniProt10a]
UniProt: (in Ref. 1; CAA34807);
Sequence-Conflict 248
[Romeo88, UniProt10a]
UniProt: (in Ref. 5; AAA23875);
Sequence-Conflict 280
[Yu88, UniProt10a]
[Romeo88, UniProt10a]
DV: (in Ref. 2; AAA23874/AAA58226);
G: (in Ref. 5; AAA23875);
Sequence-Conflict 324
[Romeo88, UniProt10a]
UniProt: (in Ref. 5; AAA23875);
Sequence-Conflict 377
[Romeo88, UniProt10a]
UniProt: (in Ref. 5; AAA23875);
Sequence-Conflict 450
[Yu88, UniProt10a]
UniProt: (in Ref. 2; AAA23874);
Sequence-Conflict 487 -> 488
[Choi89a, UniProt10a]
UniProt: (in Ref. 1; CAA34807);
Sequence-Conflict 520 -> 521
[Choi89a, UniProt10a]
UniProt: (in Ref. 1; CAA34807);
N6-pyridoxal-phosphate-Lys-Modification 662
UniProt: N6-(pyridoxal phosphate)lysine; Non-Experimental Qualifier: by similarity.
Sequence-Conflict 729
[Yu88, UniProt10a]
UniProt: (in Ref. 2; AAA23874);

10/20/97 Gene b3428 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10380; confirmed by SwissProt match.


AlonsoCasajus06: Alonso-Casajus N, Dauvillee D, Viale AM, Munoz FJ, Baroja-Fernandez E, Moran-Zorzano MT, Eydallin G, Ball S, Pozueta-Romero J (2006). "Glycogen phosphorylase, the product of the glgP Gene, catalyzes glycogen breakdown by removing glucose units from the nonreducing ends in Escherichia coli." J Bacteriol 188(14);5266-72. PMID: 16816199

Boeck96: Boeck B, Schinzel R (1996). "Purification and characterisation of an alpha-glucan phosphorylase from the thermophilic bacterium Thermus thermophilus." Eur J Biochem 239(1);150-5. PMID: 8706700

BRENDA14: BRENDA team (2014). "Imported from BRENDA version existing on Aug 2014."

Chen68: Chen GS, Segel IH (1968). "Purification and properties of glycogen phosphorylase from Escherichia coli." Arch Biochem Biophys 1968;127(1);175-86. PMID: 4878695

Chen68a: Chen GS, Segel IH (1968). "Escherichia coli polyglucose phosphorylases." Arch Biochem Biophys 1968;127(1);164-74. PMID: 4878694

Choi89a: Choi YL, Kawamukai M, Utsumi R, Sakai H, Komano T (1989). "Molecular cloning and sequencing of the glycogen phosphorylase gene from Escherichia coli." FEBS Lett 243(2);193-8. PMID: 2645169

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

Eydallin07: Eydallin G, Viale AM, Moran-Zorzano MT, Munoz FJ, Montero M, Baroja-Fernandez E, Pozueta-Romero J (2007). "Genome-wide screening of genes affecting glycogen metabolism in Escherichia coli K-12." FEBS Lett 581(16);2947-53. PMID: 17543954

Gaudet10: Gaudet P, Livstone M, Thomas P (2010). "Annotation inferences using phylogenetic trees." PMID: 19578431

GOA01: GOA, DDB, FB, MGI, ZFIN (2001). "Gene Ontology annotation through association of InterPro records with GO terms."

GOA01a: GOA, MGI (2001). "Gene Ontology annotation based on Enzyme Commission mapping." Genomics 74;121-128.

Hudson93a: Hudson JW, Golding GB, Crerar MM (1993). "Evolution of allosteric control in glycogen phosphorylase." J Mol Biol 234(3);700-21. PMID: 8254668

Romeo88: Romeo T, Kumar A, Preiss J (1988). "Analysis of the Escherichia coli glycogen gene cluster suggests that catabolic enzymes are encoded among the biosynthetic genes." Gene 70(2);363-76. PMID: 2975249

Schinzel99: Schinzel R, Nidetzky B (1999). "Bacterial alpha-glucan phosphorylases." FEMS Microbiol Lett 171(2);73-9. PMID: 10077830

Seok01: Seok YJ, Koo BM, Sondej M, Peterkofsky A (2001). "Regulation of E. coli glycogen phosphorylase activity by HPr." J Mol Microbiol Biotechnol 3(3);385-93. PMID: 11361069

Seok97: Seok YJ, Sondej M, Badawi P, Lewis MS, Briggs MC, Jaffe H, Peterkofsky A (1997). "High affinity binding and allosteric regulation of Escherichia coli glycogen phosphorylase by the histidine phosphocarrier protein, HPr." J Biol Chem 272(42);26511-21. PMID: 9334229

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

UniProt11a: UniProt Consortium (2011). "UniProt version 2011-11 released on 2011-11-22 00:00:00." Database.

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

Yu88: Yu F, Jen Y, Takeuchi E, Inouye M, Nakayama H, Tagaya M, Fukui T (1988). "Alpha-glucan phosphorylase from Escherichia coli. Cloning of the gene, and purification and characterization of the protein." J Biol Chem 1988;263(27);13706-11. PMID: 3047129

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Please cite the following article in publications resulting from the use of MetaCyc: Caspi et al, Nucleic Acids Research 42:D459-D471 2014
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