Escherichia coli K-12 substr. MG1655 Enzyme: acid phosphatase

Gene: appA Accession Numbers: EG10049 (EcoCyc), b0980, ECK0971

Regulation Summary Diagram: ?

Regulation summary diagram for appA

Subunit composition of acid phosphatase = [AppA]2

Acid phosphatase catalyzes the hydrolysis of the distal phosphoryl residues of GTP and of the regulatory nucleotide guanosine 5',3'-bisphosphate under very acidic conditions [Dassa82]. The expression of the enzyme is subject to complex regulation. It is induced by anoxia, influenced by the phase of growth, and the concentration of phosphate [Boquet87, Dassa82]. The biological significance of the pH 2.5 acid phosphatase in the periplasm of E. coli is still not understood. The enzyme is apparently not able to supply the cell with inorganic phosphate split from exogenous phosphorylated compounds or polyphosphates. Its complex regulatory characteristics, and in particular its synthesis in response to oxygen deprivation have suggested a possible relationship with fermentation or respiration [Dassa91].

Although the predominant enzymatic activity appears to be that of an acid phosphatase, there is a second enzymatic activity associated with the AppA polypeptide. This second activity is that of a phytase [Greiner93]. Phytase is expressed under anaerobic conditions and in late stationary phase growth [Greiner91]. Phytase is considered to be a special type of acid phosphatase, which is capable of splitting off phosphate from phytate as well as other diversified organophosphates. The purified E. coli phytase dephosphorylates myo-inositol hexakisphosphate in a sequential manner to produce myo-inositol monophosphate however the hydrolysis rate decreases markedly during the later steps possibly due to inhibition by the phosphate product [Greiner93, Wyss99, Greiner01].

Citations: [Dassa90, Konietzny04]

Gene Citations: [Atlung94]

Locations: periplasmic space

Map Position: [1,039,840 -> 1,041,138] (22.41 centisomes, 81°)
Length: 1299 bp / 432 aa

Molecular Weight of Polypeptide: 47.057 kD (from nucleotide sequence)

pI: 6.67

Unification Links: ASAP:ABE-0003305 , CGSC:17758 , EchoBASE:EB0047 , EcoGene:EG10049 , EcoliWiki:b0980 , ModBase:P07102 , OU-Microarray:b0980 , PortEco:appA , PR:PRO_000022109 , Pride:P07102 , Protein Model Portal:P07102 , RefSeq:NP_415500 , RegulonDB:EG10049 , SMR:P07102 , String:511145.b0980 , UniProt:P07102

Relationship Links: InterPro:IN-FAMILY:IPR000560 , InterPro:IN-FAMILY:IPR029033 , PDB:Structure:1DKL , PDB:Structure:1DKM , PDB:Structure:1DKN , PDB:Structure:1DKO , PDB:Structure:1DKP , PDB:Structure:1DKQ , Pfam:IN-FAMILY:PF00328 , Prosite:IN-FAMILY:PS00616 , Prosite:IN-FAMILY:PS00778

In Paralogous Gene Group: 234 (2 members)

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for appA

GO Terms:

Biological Process: GO:0016036 - cellular response to phosphate starvation Inferred from experiment [Dassa82]
GO:0016311 - dephosphorylation Inferred from experiment Inferred by computational analysis [GOA01, GOA01a, Greiner93, Dassa82]
GO:0071454 - cellular response to anoxia Inferred from experiment [Dassa82]
GO:0008152 - metabolic process Inferred by computational analysis [UniProtGOA11a]
Molecular Function: GO:0003993 - acid phosphatase activity Inferred from experiment Inferred by computational analysis [GOA01, GOA01a, Dassa82]
GO:0008707 - 4-phytase activity Inferred from experiment Inferred by computational analysis [GOA01, Greiner93]
GO:0003824 - catalytic activity Inferred by computational analysis [UniProtGOA11a]
GO:0016787 - hydrolase activity Inferred by computational analysis [UniProtGOA11a]
Cellular Component: GO:0042597 - periplasmic space Inferred from experiment Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, Tetu79]
GO:0030288 - outer membrane-bounded periplasmic space Inferred by computational analysis [DiazMejia09, Tetu79]

MultiFun Terms: cell processes adaptations starvation
metabolism metabolism of other compounds phosphorous metabolism

Essentiality data for appA knockouts: ?

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB enriched Yes 37 Aerobic 6.95   Yes [Gerdes03, Comment 1]
LB Lennox Yes 37 Aerobic 7   Yes [Baba06, Comment 2]
M9 medium with 1% glycerol Yes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 3]
MOPS medium with 0.4% glucose Yes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 2]
Yes [Feist07, Comment 4]

Last-Curated ? 07-Apr-2011 by Mackie A , Macquarie University

Enzymatic reaction of: phytase (acid phosphatase)

EC Number:

1D-myo-inositol 1,2,3,4,5,6-hexakisphosphate[periplasmic space] + H2O[periplasmic space] <=> D-myo-inositol (1,2,3,4,5)-pentakisphosphate[periplasmic space] + phosphate[periplasmic space]

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the direction shown.

Enzymatic reaction of: pH 2.5 acid phosphatase

Synonyms: phosphoanhydride phosphohydrolase, acid phosphomonoesterase, phosphomonoesterase, glycerophosphatase, acid phosphatase

EC Number:

GTP + H2O <=> GDP + phosphate + H+

The reaction direction shown, that is, A + B ↔ C + D versus C + D ↔ A + B, is in accordance with the direction in which it was curated.

The reaction is physiologically favored in the direction shown.

Alternative Substrates [Comment 5]:

Inhibitors (Competitive): fusidate [Dassa82] , NaF [Dassa82] , L-tartrate [Dassa82]

Inhibitors (Unknown Mechanism): oxalate [Dassa82, Comment 6]

Sequence Features

Protein sequence of AppA with features indicated

Feature Class Location Citations Comment
Signal-Sequence 1 -> 22
[Greiner91a, Greiner93, Dassa90, UniProt12a]
Chain 23 -> 432
UniProt: Periplasmic appA protein;
Amino-Acid-Sites-That-Bind 38
UniProt: Substrate.
Active-Site 39
UniProt: Nucleophile.
Protein-Segment 42 -> 46
UniProt: Substrate binding; Sequence Annotation Type: region of interest.
Sequence-Conflict 51 -> 66
[Touati87, UniProt10a]
UniProt: (in Ref. 5; CAA29031);
Sequence-Conflict 75 -> 76
[Touati87, UniProt10a]
UniProt: (in Ref. 5; CAA29031);
Disulfide-Bond-Site 99, 130
Sequence-Conflict 112
[Touati87, UniProt10a]
UniProt: (in Ref. 5; CAA29031);
Amino-Acid-Sites-That-Bind 114
UniProt: Substrate.
Disulfide-Bond-Site 155, 430
Disulfide-Bond-Site 200, 210
Amino-Acid-Sites-That-Bind 289
UniProt: Substrate.
Protein-Segment 325 -> 327
UniProt: Substrate binding; Sequence Annotation Type: region of interest.
Active-Site 326
UniProt: Proton donor.
Disulfide-Bond-Site 404, 413

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Units:

Transcription-unit diagram

Transcription-unit diagram


10/20/97 Gene b0980 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10049; confirmed by SwissProt match.


Atlung94: Atlung T, Brondsted L (1994). "Role of the transcriptional activator AppY in regulation of the cyx appA operon of Escherichia coli by anaerobiosis, phosphate starvation, and growth phase." J Bacteriol 1994;176(17);5414-22. PMID: 8071219

Baba06: Baba T, Ara T, Hasegawa M, Takai Y, Okumura Y, Baba M, Datsenko KA, Tomita M, Wanner BL, Mori H (2006). "Construction of Escherichia coli K-12 in-frame, single-gene knockout mutants: the Keio collection." Mol Syst Biol 2;2006.0008. PMID: 16738554

Boquet87: Boquet PL, Manoil C, Beckwith J (1987). "Use of TnphoA to detect genes for exported proteins in Escherichia coli: identification of the plasmid-encoded gene for a periplasmic acid phosphatase." J Bacteriol 1987;169(4);1663-9. PMID: 3031017

Dassa82: Dassa E, Cahu M, Desjoyaux-Cherel B, Boquet PL (1982). "The acid phosphatase with optimum pH of 2.5 of Escherichia coli. Physiological and Biochemical study." J Biol Chem 1982;257(12);6669-76. PMID: 6282821

Dassa90: Dassa J, Marck C, Boquet PL (1990). "The complete nucleotide sequence of the Escherichia coli gene appA reveals significant homology between pH 2.5 acid phosphatase and glucose-1-phosphatase." J Bacteriol 172(9);5497-500. PMID: 2168385

Dassa91: Dassa J, Fsihi H, Marck C, Dion M, Kieffer-Bontemps M, Boquet PL (1991). "A new oxygen-regulated operon in Escherichia coli comprises the genes for a putative third cytochrome oxidase and for pH 2.5 acid phosphatase (appA)." Mol Gen Genet 1991;229(3);341-52. PMID: 1658595

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

Feist07: Feist AM, Henry CS, Reed JL, Krummenacker M, Joyce AR, Karp PD, Broadbelt LJ, Hatzimanikatis V, Palsson BO (2007). "A genome-scale metabolic reconstruction for Escherichia coli K-12 MG1655 that accounts for 1260 ORFs and thermodynamic information." Mol Syst Biol 3;121. PMID: 17593909

Gerdes03: Gerdes SY, Scholle MD, Campbell JW, Balazsi G, Ravasz E, Daugherty MD, Somera AL, Kyrpides NC, Anderson I, Gelfand MS, Bhattacharya A, Kapatral V, D'Souza M, Baev MV, Grechkin Y, Mseeh F, Fonstein MY, Overbeek R, Barabasi AL, Oltvai ZN, Osterman AL (2003). "Experimental determination and system level analysis of essential genes in Escherichia coli MG1655." J Bacteriol 185(19);5673-84. PMID: 13129938

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."

Greiner01: Greiner R, Carlsson N, Alminger ML (2001). "Stereospecificity of myo-inositol hexakisphosphate dephosphorylation by a phytate-degrading enzyme of Escherichia coli." J Biotechnol 84(1);53-62. PMID: 11035187

Greiner91: Greiner R, Jany K-D "Characterization of a phytase from Escherichia coli." Biol Chem Hoppe-Seyler 1991;372:664-665.

Greiner91a: Greiner R., Jany K.-D. (1991). "Characterization of a phytase from Escherichia coli." Biol. Chem. Hoppe-Seyler, Volume 372, page(s) 664-665.

Greiner93: Greiner R, Konietzny U, Jany KD (1993). "Purification and characterization of two phytases from Escherichia coli." Arch Biochem Biophys 1993;303(1);107-13. PMID: 8387749

Joyce06: Joyce AR, Reed JL, White A, Edwards R, Osterman A, Baba T, Mori H, Lesely SA, Palsson BO, Agarwalla S (2006). "Experimental and computational assessment of conditionally essential genes in Escherichia coli." J Bacteriol 188(23);8259-71. PMID: 17012394

Konietzny04: Konietzny U, Greiner R (2004). "Bacterial phytase: potential application, in vivo function and regulation of its synthesis." Brazilian Journal of Microbiology 2004 35: 11-18.

Tetu79: Tetu C, Dassa E, Boquet PL (1979). "Unusual pattern of nucleoside polyphosphate hydrolysis by the acid phosphatase (optimum pH = 2.5) of Escherichia coli." Biochem Biophys Res Commun 1979;87(1);314-22. PMID: 378222

Touati87: Touati E, Danchin A (1987). "The structure of the promoter and amino terminal region of the pH 2.5 acid phosphatase structural gene (appA) of E. coli: a negative control of transcription mediated by cyclic AMP." Biochimie 69(3);215-21. PMID: 3038201

UniProt09: UniProt Consortium (2009). "UniProt version 15.8 released on 2009-10-01 00:00:00." Database.

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

UniProt12: UniProt Consortium (2012). "UniProt version 2012-09 released on 2012-09-12 00:00:00." Database.

UniProt12a: UniProt Consortium (2012). "UniProt version 2012-02 released on 2012-02-29 00:00:00." Database.

UniProt15: UniProt Consortium (2015). "UniProt version 2015-01 released on 2015-01-16 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."

Wyss99: Wyss M, Brugger R, Kronenberger A, Remy R, Fimbel R, Oesterhelt G, Lehmann M, van Loon AP (1999). "Biochemical characterization of fungal phytases (myo-inositol hexakisphosphate phosphohydrolases): catalytic properties." Appl Environ Microbiol 65(2);367-73. PMID: 9925555

Other References Related to Gene Regulation

Atlung97: Atlung T, Knudsen K, Heerfordt L, Brondsted L (1997). "Effects of sigmaS and the transcriptional activator AppY on induction of the Escherichia coli hya and cbdAB-appA operons in response to carbon and phosphate starvation." J Bacteriol 179(7);2141-6. PMID: 9079897

Brondsted96: Brondsted L, Atlung T (1996). "Effect of growth conditions on expression of the acid phosphatase (cyx-appA) operon and the appY gene, which encodes a transcriptional activator of Escherichia coli." J Bacteriol 1996;178(6);1556-64. PMID: 8626281

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Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
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