Escherichia coli K-12 substr. MG1655 Enzyme: L-ascorbate 6-phosphate lactonase

Gene: ulaG Accession Numbers: G7855 (EcoCyc), b4192, ECK4188

Synonyms: yjfR

Regulation Summary Diagram: ?

Regulation summary diagram for ulaG

Subunit composition of L-ascorbate 6-phosphate lactonase = [UlaG]6
         L-ascorbate 6-phosphate lactonase = UlaG

UlaG is required for the ability to utilize L-ascorbate as the sole carbon source under anaerobic growth conditions. The enzyme was suggested to be a cytoplasmic L-ascorbate 6-phosphate lactonase [Zhang03h], and its catalytic activity has recently been shown [Garces10]. Phosphodiesterase activity of UlaG was discovered in a high-throughput screen of purified proteins [Kuznetsova05].

Crystal structures of the UlaG apoenzyme and the Mn2+-bound holoenzyme have been solved at 2.6 Å resolution [Garces08, Garces10]. Phylogenetic analysis of the UlaG-like protein family indicates that it has a common evolutionary origin with RNA processing and metabolizing metallo-β-lactamases [Fernandez11].

Expression of ulaG is negatively regulated by UlaR [Campos02].

Gene Citations: [Campos04]

Locations: cytosol

Map Position: [4,416,584 <- 4,417,648] (95.19 centisomes, 343°)
Length: 1065 bp / 354 aa

Molecular Weight of Polypeptide: 40.061 kD (from nucleotide sequence)

Molecular Weight of Multimer: 256.0 kD (experimental) [Garces08]

Unification Links: ASAP:ABE-0013717 , DIP:DIP-12596N , EchoBASE:EB2385 , EcoGene:EG12492 , EcoliWiki:b4192 , ModBase:P39300 , OU-Microarray:b4192 , PortEco:ulaG , Pride:P39300 , Protein Model Portal:P39300 , RefSeq:NP_418613 , RegulonDB:G7855 , SMR:P39300 , String:511145.b4192 , UniProt:P39300

Relationship Links: InterPro:IN-FAMILY:IPR001279 , InterPro:IN-FAMILY:IPR023951 , PDB:Structure:2WYL , PDB:Structure:2WYM , Smart:IN-FAMILY:SM00849

Gene-Reaction Schematic: ?

Gene-Reaction Schematic

Genetic Regulation Schematic: ?

Genetic regulation schematic for ulaG

GO Terms:

Biological Process: GO:0019854 - L-ascorbic acid catabolic process Inferred from experiment Inferred by computational analysis [UniProtGOA12, GOA06, GOA01a, Zhang03h]
Molecular Function: GO:0030145 - manganese ion binding Inferred from experiment Inferred by computational analysis [GOA01a, Garces10]
GO:0035460 - L-ascorbate 6-phosphate lactonase activity Inferred from experiment Inferred by computational analysis [GOA01a, Garces10]
GO:0016787 - hydrolase activity Inferred by computational analysis [UniProtGOA11a]
GO:0052689 - carboxylic ester hydrolase activity Inferred by computational analysis [GOA06]
Cellular Component: GO:0005737 - cytoplasm Inferred by computational analysis [UniProtGOA11, UniProtGOA11a, GOA06]
GO:0005829 - cytosol

MultiFun Terms: metabolism carbon utilization

Essentiality data for ulaG 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]

Created 12-Apr-2010 by Keseler I , SRI International
Last-Curated ? 02-Mar-2012 by Keseler I , SRI International

Enzymatic reaction of: L-ascorbate 6-phosphate lactonase

EC Number: 3.1.1.-

L-ascorbate 6-phosphate + H2O <=> 3-keto-L-gulonate 6-phosphate

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.

In Pathways: L-ascorbate degradation I (bacterial, anaerobic)

Co2+ can substitute for Mn2+ [Garces10].

Cofactors or Prosthetic Groups: Mn2+ [Garces10]

Kinetic Parameters:

Km (μM)
L-ascorbate 6-phosphate

Gene Local Context (not to scale): ?

Gene local context diagram

Transcription Unit:

Transcription-unit diagram


Peter D. Karp on Wed Jan 18, 2006:
Gene right-end position adjusted based on analysis performed in the 2005 E. coli annotation update [Riley06 ].
Peter D. Karp on Thu Jan 16, 2003:
Predicted gene function revised as a result of E. coli genome reannotation by Serres et al. [Serres01 ].
Markus Krummenacker on Tue Oct 14, 1997:
Gene object created from Blattner lab Genbank (v. M52) entry.


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

Campos02: Campos E, Aguilar J, Baldoma L, Badia J (2002). "The gene yjfQ encodes the repressor of the yjfR-X regulon (ula), which is involved in L-ascorbate metabolism in Escherichia coli." J Bacteriol 184(21);6065-8. PMID: 12374842

Campos04: Campos E, Baldoma L, Aguilar J, Badia J (2004). "Regulation of expression of the divergent ulaG and ulaABCDEF operons involved in LaAscorbate dissimilation in Escherichia coli." J Bacteriol 186(6);1720-8. PMID: 14996803

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

Fernandez11: Fernandez FJ, Garces F, Lopez-Estepa M, Aguilar J, Baldoma L, Coll M, Badia J, Vega MC (2011). "The UlaG protein family defines novel structural and functional motifs grafted on an ancient RNase fold." BMC Evol Biol 11;273. PMID: 21943130

Garces08: Garces F, Fernandez FJ, Perez-Luque R, Aguilar J, Baldoma L, Coll M, Badia J, Vega MC (2008). "Overproduction, crystallization and preliminary X-ray analysis of the putative L-ascorbate-6-phosphate lactonase UlaG from Escherichia coli." Acta Crystallogr Sect F Struct Biol Cryst Commun 64(Pt 1);36-8. PMID: 18097099

Garces10: Garces F, Fernandez FJ, Montella C, Penya-Soler E, Prohens R, Aguilar J, Baldoma L, Coll M, Badia J, Vega MC (2010). "Molecular architecture of the Mn2+-dependent lactonase UlaG reveals an RNase-like metallo-beta-lactamase fold and a novel quaternary structure." J Mol Biol 398(5);715-29. PMID: 20359483

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

GOA06: GOA, SIB (2006). "Electronic Gene Ontology annotations created by transferring manual GO annotations between orthologous microbial proteins."

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

Kuznetsova05: Kuznetsova E, Proudfoot M, Sanders SA, Reinking J, Savchenko A, Arrowsmith CH, Edwards AM, Yakunin AF (2005). "Enzyme genomics: Application of general enzymatic screens to discover new enzymes." FEMS Microbiol Rev 29(2);263-79. PMID: 15808744

Riley06: Riley M, Abe T, Arnaud MB, Berlyn MK, Blattner FR, Chaudhuri RR, Glasner JD, Horiuchi T, Keseler IM, Kosuge T, Mori H, Perna NT, Plunkett G, Rudd KE, Serres MH, Thomas GH, Thomson NR, Wishart D, Wanner BL (2006). "Escherichia coli K-12: a cooperatively developed annotation snapshot--2005." Nucleic Acids Res 34(1);1-9. PMID: 16397293

Serres01: Serres MH, Gopal S, Nahum LA, Liang P, Gaasterland T, Riley M (2001). "A functional update of the Escherichia coli K-12 genome." Genome Biol 2(9);RESEARCH0035. PMID: 11574054

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."

UniProtGOA12: UniProt-GOA (2012). "Gene Ontology annotation based on UniPathway vocabulary mapping."

Zhang03h: Zhang Z, Aboulwafa M, Smith MH, Saier MH (2003). "The ascorbate transporter of Escherichia coli." J Bacteriol 185(7);2243-50. PMID: 12644495

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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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