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Escherichia coli K-12 substr. MG1655 Enzyme: nucleoside triphosphate pyrophosphohydrolase



Gene: mazG Accession Numbers: EG10572 (EcoCyc), b2781, ECK2775

Regulation Summary Diagram: ?

Subunit composition of nucleoside triphosphate pyrophosphohydrolase = [MazG]2
         nucleoside triphosphate pyrophosphohydrolase = MazG

Summary:
MazG is a nucleoside pyrophosphohydrolase that limits the deleterious effect of the MazF toxin under nutritional stress conditions [Zhang02, Gross06]. MazF belongs to the superfamily of all-α NTP pyrophosphatases. Members of this family are predicted to perform "house-cleaning" functions by hydrolyzing non-canonical NTPs [Moroz05].

MazG exhibits pyrophosphohydrolase activity toward all four dNTPs and also exhibits (somewhat less) activity toward all four rNTPs [Zhang02]. Hydrolysis of GTP is more efficient that hydrolysis of ATP [Gross06]. Addition of purified MazEF proteins causes inhibition of MazG enzymatic activity [Gross06].

MazG and Era associate in vitro and by yeast two-hybrid test. Nucleotide influences the association; binding is weaker with GTPγS than with GDP added [Zhang02].

Crystal structures of MazG alone and in complex with ATP have been solved. MazG is a dimer in the crystal structure, and each monomer contains two domains with similar folds. Point mutations in potential active site residues and domain deletion mutants showed that the NTP pyrophosphohydrolase activity is located in the C-terminal domain [Lee08c].

Overexpression of mazG inhibits cell growth and negatively affects accumulation of (p)ppGpp, while overexpression of the entire mazEFG operon has no effect on cell growth or (p)ppGpp accumulation. A mazG deletion mutant is less able to survive under nutritional stress conditions [Gross06].

Review: [Galperin06]

Gene Citations: [Metzger88, Masuda93, Aizenman96, Marianovsky01]

Locations: cytosol

Map Position: [2,907,916 <- 2,908,707] (62.67 centisomes)
Length: 792 bp / 263 aa

Molecular Weight of Polypeptide: 30.412 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0009117 , DIP:DIP-48054N , EchoBASE:EB0567 , EcoGene:EG10572 , EcoliWiki:b2781 , Mint:MINT-1311211 , OU-Microarray:b2781 , PortEco:mazG , PR:PRO_000023168 , Protein Model Portal:P0AEY3 , RefSeq:NP_417261 , RegulonDB:EG10572 , SMR:P0AEY3 , String:511145.b2781 , UniProt:P0AEY3

Relationship Links: InterPro:IN-FAMILY:IPR004518 , InterPro:IN-FAMILY:IPR011551 , PDB:Structure:3CRA , PDB:Structure:3CRC , Pfam:IN-FAMILY:PF03819

Gene-Reaction Schematic: ?

Instance reactions of [a nucleoside triphosphate + H2O → a nucleoside 5'-monophosphate + diphosphate + H+] (3.6.1.19):
i1: CTP + H2O → CMP + diphosphate + H+ (3.6.1.65)

i2: dATP + H2O → dAMP + diphosphate + H+ (3.6.1.19)

i3: dUTP + H2O → dUMP + diphosphate + H+ (3.6.1.19/3.6.1.23)

i4: dGTP + H2O → dGMP + diphosphate + H+ (3.6.1.19)

i5: dITP + H2O → dIMP + diphosphate + H+ (3.6.1.66)

i6: ITP + H2O → IMP + diphosphate + H+ (3.6.1.19)

i7: XTP + H2O → XMP + diphosphate + H+ (3.6.1.66)

i8: ATP + H2O → AMP + diphosphate + H+ (3.6.1.8)

i9: dTTP + H2O → dTMP + diphosphate + H+ (3.6.1.19)

i10: UTP + H2O → UMP + diphosphate + H+ (3.6.1.19)

i11: dCTP + H2O → dCMP + diphosphate + H+ (3.6.1.12/3.6.1.19/3.6.1.65)

Genetic Regulation Schematic: ?

GO Terms:

Biological Process: GO:0008152 - metabolic process Inferred by computational analysis Inferred from experiment [Zhang02, UniProtGOA11, GOA01a]
GO:0009267 - cellular response to starvation Inferred from experiment [Gross06]
Molecular Function: GO:0005515 - protein binding Inferred from experiment [Zhang02]
GO:0047429 - nucleoside-triphosphate diphosphatase activity Inferred from experiment [Zhang02]
GO:0000166 - nucleotide binding Inferred by computational analysis [UniProtGOA11]
GO:0005524 - ATP binding Inferred by computational analysis [UniProtGOA11]
GO:0016787 - hydrolase activity Inferred by computational analysis [UniProtGOA11]
GO:0046872 - metal ion binding Inferred by computational analysis [UniProtGOA11]
GO:0047693 - ATP diphosphatase activity Inferred by computational analysis [GOA01a]
Cellular Component: GO:0005829 - cytosol Inferred by computational analysis [DiazMejia09]

MultiFun Terms: cell processes adaptations starvation

Essentiality data for mazG 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]

Credits:
Created 16-May-2008 by Keseler I , SRI International
Last-Curated ? 16-May-2008 by Keseler I , SRI International


Enzymatic reaction of: nucleoside triphosphate pyrophosphohydrolase

Synonyms: nucleoside-triphosphate pyrophosphatase, nucleoside-triphosphate diphosphohydrolase

EC Number: 3.6.1.19

a nucleoside triphosphate + H2O <=> a nucleoside 5'-monophosphate + diphosphate + H+

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.

In Pathways: superpathway of pyrimidine deoxyribonucleotides de novo biosynthesis (E. coli) , superpathway of pyrimidine deoxyribonucleotides de novo biosynthesis , pyrimidine deoxyribonucleotides de novo biosynthesis I , pyrimidine deoxyribonucleotides dephosphorylation , pyrimidine deoxyribonucleotides de novo biosynthesis II

Cofactors or Prosthetic Groups: Mg2+ [Comment 5, Zhang02]

Inhibitors (Unknown Mechanism): MazE-MazF antitoxin/toxin complex and DNA-binding transcriptional repressor [Gross06]

pH(opt): 9.5 [Zhang02]


Sequence Features

Feature Class Location Citations Comment
Mutagenesis-Variant 95
[Lee08c, UniProt11]
Alternate sequence: R → A; UniProt: Does not affect nucleotide pyrophosphohydrolysis activity.
Mutagenesis-Variant 119
[Lee08c, UniProt11]
Alternate sequence: K → A; UniProt: Does not affect the nucleotide pyrophosphohydrolysis activity.
Mutagenesis-Variant 168
[Lee08c, UniProt11]
Alternate sequence: K → A; UniProt: Does not affect nucleotide pyrophosphohydrolysis activity.
Nucleotide-Phosphate-Binding-Region 168 -> 172
[UniProt10b]
UniProt: ATP 1;
Mutagenesis-Variant 171
[Lee08c, UniProt11]
Alternate sequence: E → A; UniProt: Does not affect nucleotide pyrophosphohydrolysis activity.
Mutagenesis-Variant 172
[Lee08c, UniProt11]
Alternate sequence: E → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.
Metal-Binding-Site 172
[UniProt10b]
UniProt: Magnesium;
Mutagenesis-Variant 175
[Lee08c, UniProt11]
Alternate sequence: E → A; UniProt: Does not affect nucleotide pyrophosphohydrolysis activity.
Metal-Binding-Site 175
[UniProt10b]
UniProt: Magnesium;
Mutagenesis-Variant 189
[Lee08c, UniProt11]
Alternate sequence: K → A; UniProt: Does not affect nucleotide pyrophosphohydrolysis activity.
Nucleotide-Phosphate-Binding-Region 189 -> 192
[UniProt10b]
UniProt: ATP 1;
Mutagenesis-Variant 192
[Lee08c, UniProt11]
Alternate sequence: E → A; UniProt: Does not affect nucleotide pyrophosphohydrolysis activity.
Mutagenesis-Variant 193
[Lee08c, UniProt11]
Alternate sequence: E → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.
Metal-Binding-Site 193
[UniProt10b]
UniProt: Magnesium;
Mutagenesis-Variant 196
[Lee08c, UniProt11]
Alternate sequence: D → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.
Metal-Binding-Site 196
[UniProt10b]
UniProt: Magnesium;
Mutagenesis-Variant 222
[Lee08c, UniProt11]
Alternate sequence: K → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.
Nucleotide-Phosphate-Binding-Region 222 -> 226
[UniProt10b]
UniProt: ATP 2;
Mutagenesis-Variant 226
[Lee08c, UniProt11]
Alternate sequence: R → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.
Sequence-Conflict 226
[Aizenman93, UniProt10]
Alternate sequence: R → missing; UniProt: (in Ref. 1; AAA03240);
Mutagenesis-Variant 253
[Lee08c, UniProt11]
Alternate sequence: W → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.
Amino-Acid-Sites-That-Bind 253
[UniProt10b]
UniProt: ATP 2;
Mutagenesis-Variant 257
[Lee08c, UniProt11]
Alternate sequence: K → A; UniProt: Loss of pyrophosphohydrolysis activity against both ATP and dTTP.


Gene Local Context (not to scale): ?

Transcription Units:

Notes:

History:
10/20/97 Gene b2781 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10572; confirmed by SwissProt match.


References

Aizenman93: Aizenman E., Glaser G. (1993). Data submission to EMBL/GenBank/DDBJ databases on 1993-11.

Aizenman96: Aizenman E, Engelberg-Kulka H, Glaser G (1996). "An Escherichia coli chromosomal "addiction module" regulated by guanosine [corrected] 3',5'-bispyrophosphate: a model for programmed bacterial cell death." Proc Natl Acad Sci U S A 1996;93(12);6059-63. PMID: 8650219

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

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

Galperin06: Galperin MY, Moroz OV, Wilson KS, Murzin AG (2006). "House cleaning, a part of good housekeeping." Mol Microbiol 59(1);5-19. PMID: 16359314

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

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

Gross06: Gross M, Marianovsky I, Glaser G (2006). "MazG - a regulator of programmed cell death in Escherichia coli." Mol Microbiol 59(2);590-601. PMID: 16390452

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

Lee08c: Lee S, Kim MH, Kang BS, Kim JS, Kim GH, Kim YG, Kim KJ (2008). "Crystal structure of Escherichia coli MazG, the regulator of nutritional stress response." J Biol Chem 283(22):15232-40. PMID: 18353782

Marianovsky01: Marianovsky I, Aizenman E, Engelberg-Kulka H, Glaser G (2001). "The regulation of the Escherichia coli mazEF promoter involves an unusual alternating palindrome." J Biol Chem 2001;276(8);5975-84. PMID: 11071896

Masuda93: Masuda Y, Miyakawa K, Nishimura Y, Ohtsubo E (1993). "chpA and chpB, Escherichia coli chromosomal homologs of the pem locus responsible for stable maintenance of plasmid R100." J Bacteriol 1993;175(21);6850-6. PMID: 8226627

Metzger88: Metzger S, Dror IB, Aizenman E, Schreiber G, Toone M, Friesen JD, Cashel M, Glaser G (1988). "The nucleotide sequence and characterization of the relA gene of Escherichia coli." J Biol Chem 1988;263(30);15699-704. PMID: 2844820

Moroz05: Moroz OV, Murzin AG, Makarova KS, Koonin EV, Wilson KS, Galperin MY (2005). "Dimeric dUTPases, HisE, and MazG belong to a new superfamily of all-alpha NTP pyrophosphohydrolases with potential "house-cleaning" functions." J Mol Biol 347(2);243-55. PMID: 15740738

UniProt10: UniProt Consortium (2010). "UniProt version 2010-11 released on 2010-11-02 00:00:00." Database.

UniProt10b: UniProt Consortium (2010). "UniProt version 2010-12 released on 2010-12-01 00:00:00." Database.

UniProt11: UniProt Consortium (2011). "UniProt version 2011-06 released on 2011-06-30 00:00:00." Database.

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

Zhang02: Zhang J, Inouye M (2002). "MazG, a nucleoside triphosphate pyrophosphohydrolase, interacts with Era, an essential GTPase in Escherichia coli." J Bacteriol 184(19);5323-9. PMID: 12218018

Other References Related to Gene Regulation

KolodkinGal09a: Kolodkin-Gal I, Engelberg-Kulka H (2009). "The stationary-phase sigma factor sigma(S) is responsible for the resistance of Escherichia coli stationary-phase cells to mazEF-mediated cell death." J Bacteriol 191(9);3177-82. PMID: 19251848


Report Errors or Provide Feedback
Please cite the following article in publications resulting from the use of EcoCyc: Nucleic Acids Research 41:D605-12 2013
Page generated by SRI International Pathway Tools version 18.5 on Mon Nov 24, 2014, biocyc13.