|Gene:||umpH||Accession Numbers: EG10634 (EcoCyc), b0675, ECK0663|
UmpH is a ribonucleoside tri-, di-, and monophosphatase with a preference for purines [Tremblay06]. The enzyme was found to degrade "overflow" UMP nucleotides and is required for optimal growth in response to environmental pyrimidine intermediates [Reaves13]. UMP accumulation to levels above the Km of the enzyme, triggered by environmental conditions or artificially induced by mutations in the normal feedback regulation of the pyrimidine biosynthesis pathway, appear to cause the overflow degradation of UMP by UmpH [Reaves13].
Though UmpH is a member of the nag N-acetylglucosamine utilization operon, it is a fairly general ribonucleotide monophosphatase [Peri90, Tremblay06, Kuznetsova06]. A type IIA member of the HAD protein superfamily, UmpH shows peak activity with UMP, but is also a very effective phosphatase with AMP, GMP and CMP [Koonin94, Tremblay06].
The structure of UmpH has been solved to 1.8 Å resolution [Tremblay06].
A umpH null mutant shows somewhat impaired growth upon addition of orotate, an intermediate in the pyrimidine biosynthesis pathway, to the growth medium. However, growth recovers, and the final culture density is higher than for wild type cells [Reaves13]. Overexpression of umpH induces a stress response, including increased expression of rpoH, and enables improved expression of certain recombinant membrane proteins [Skretas12].
UmpH: "UMP degradation" [Reaves13]
|Map Position: [698,797 <- 699,549] (15.06 centisomes)||Length: 753 bp / 250 aa|
Molecular Weight of Polypeptide: 27.163 kD (from nucleotide sequence)
Unification Links: ASAP:ABE-0002296 , CGSC:36240 , EchoBASE:EB0628 , EcoGene:EG10634 , EcoliWiki:b0675 , ModBase:P0AF24 , OU-Microarray:b0675 , PortEco:nagD , PR:PRO_000023339 , Pride:P0AF24 , Protein Model Portal:P0AF24 , RefSeq:NP_415201 , RegulonDB:EG10634 , SMR:P0AF24 , String:511145.b0675 , Swiss-Model:P0AF24 , UniProt:P0AF24
Instance reactions of [a ribonucleoside 5'-monophosphate + H2O → a ribonucleoside + phosphate] (220.127.116.11):
|Biological Process:||GO:0016311 - dephosphorylation
GO:0046050 - UMP catabolic process [Reaves13]
GO:0005975 - carbohydrate metabolic process [UniProtGOA11a]
|Molecular Function:||GO:0000287 - magnesium ion binding
GO:0008253 - 5'-nucleotidase activity [GOA01, Tremblay06]
GO:0016787 - hydrolase activity [UniProtGOA11a]
GO:0046872 - metal ion binding [UniProtGOA11a]
|Cellular Component:||GO:0005829 - cytosol [DiazMejia09, Ishihama08]|
|MultiFun Terms:||metabolism → biosynthesis of building blocks → nucleotides → pyrimidine ribonucleotide biosynthesis|
|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]|
Enzymatic reaction of: UMP phosphatase
Synonyms: HAD23, ribonucleotide monophosphatase
EC Number: 18.104.22.168
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.
|Protein-Segment||42 -> 43|
|Protein-Segment||202 -> 205|
10/20/97 Gene b0675 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10634; confirmed by SwissProt match.
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
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
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
Koonin94: Koonin EV, Tatusov RL (1994). "Computer analysis of bacterial haloacid dehalogenases defines a large superfamily of hydrolases with diverse specificity. Application of an iterative approach to database search." J Mol Biol 244(1);125-32. PMID: 7966317
Kuznetsova06: Kuznetsova E, Proudfoot M, Gonzalez CF, Brown G, Omelchenko MV, Borozan I, Carmel L, Wolf YI, Mori H, Savchenko AV, Arrowsmith CH, Koonin EV, Edwards AM, Yakunin AF (2006). "Genome-wide analysis of substrate specificities of the Escherichia coli haloacid dehalogenase-like phosphatase family." J Biol Chem 281(47):36149-61. PMID: 16990279
Plumbridge91a: Plumbridge JA (1991). "Repression and induction of the nag regulon of Escherichia coli K-12: the roles of nagC and nagA in maintenance of the uninduced state." Mol Microbiol 1991;5(8);2053-62. PMID: 1766379
Proudfoot04: Proudfoot M, Kuznetsova E, Brown G, Rao NN, Kitagawa M, Mori H, Savchenko A, Yakunin AF (2004). "General enzymatic screens identify three new nucleotidases in Escherichia coli. Biochemical characterization of SurE, YfbR, and YjjG." J Biol Chem 279(52);54687-94. PMID: 15489502
Rogers88: Rogers MJ, Ohgi T, Plumbridge J, Soll D (1988). "Nucleotide sequences of the Escherichia coli nagE and nagB genes: the structural genes for the N-acetylglucosamine transport protein of the bacterial phosphoenolpyruvate: sugar phosphotransferase system and for glucosamine-6-phosphate deaminase." Gene 1988;62(2);197-207. PMID: 3284790
Skretas12: Skretas G, Makino T, Varadarajan N, Pogson M, Georgiou G (2012). "Multi-copy genes that enhance the yield of mammalian G protein-coupled receptors in Escherichia coli." Metab Eng 14(5);591-602. PMID: 22609824
Tremblay06: Tremblay LW, Dunaway-Mariano D, Allen KN (2006). "Structure and activity analyses of Escherichia coli K-12 NagD provide insight into the evolution of biochemical function in the haloalkanoic acid dehalogenase superfamily." Biochemistry 45(4);1183-93. PMID: 16430214
Plumbridge01: Plumbridge J (2001). "DNA binding sites for the Mlc and NagC proteins: regulation of nagE, encoding the N-acetylglucosamine-specific transporter in Escherichia coli." Nucleic Acids Res 29(2);506-14. PMID: 11139621
Plumbridge93: Plumbridge J, Kolb A (1993). "DNA loop formation between Nag repressor molecules bound to its two operator sites is necessary for repression of the nag regulon of Escherichia coli in vivo." Mol Microbiol 10(5);973-81. PMID: 7934873
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