Escherichia coli K-12 substr. MG1655 Polypeptide: evolved β-D-galactosidase, β subunit; cryptic gene

Gene: ebgC Accession Numbers: EG10253 (EcoCyc), b3077, ECK3067

Regulation Summary Diagram

Regulation summary diagram for ebgC

Component of: evolved β-D-galactosidase (summary available)

Gene Citations: [Elliott92]

Locations: cytosol

Map Position: [3,223,744 -> 3,224,193] (69.48 centisomes, 250°)
Length: 450 bp / 149 aa

Molecular Weight of Polypeptide: 17.457 kD (from nucleotide sequence)

Unification Links: ASAP:ABE-0010106, CGSC:18412, DIP:DIP-2894N, EchoBASE:EB0249, EcoGene:EG10253, EcoliWiki:b3077, ModBase:P0AC73, OU-Microarray:b3077, PortEco:ebgC, PR:PRO_000022498, Pride:P0AC73, Protein Model Portal:P0AC73, RefSeq:NP_417548, RegulonDB:EG10253, String:511145.b3077, UniProt:P0AC73

Relationship Links: InterPro:IN-FAMILY:IPR004375, Pfam:IN-FAMILY:PF04074

Gene-Reaction Schematic

Gene-Reaction Schematic

Genetic Regulation Schematic

Genetic regulation schematic for ebgC

GO Terms:
Cellular Component:
Inferred by computational analysisGO:0005829 - cytosol [DiazMejia09]

MultiFun Terms: All-GenesPseudo-GenesCryptic-Genes
MultiFunmetabolismcarbon utilizationcarbon compounds

Essentiality data for ebgC knockouts:

Growth Medium Growth? T (°C) O2 pH Osm/L Growth Observations
LB enrichedYes 37 Aerobic 6.95   Yes [Gerdes03, Comment 1]
LB LennoxYes 37 Aerobic 7   Yes [Baba06, Comment 2]
M9 medium with 1% glycerolYes 37 Aerobic 7.2 0.35 Yes [Joyce06, Comment 3]
MOPS medium with 0.4% glucoseYes 37 Aerobic 7.2 0.22 Yes [Baba06, Comment 2]

Subunit of: evolved β-D-galactosidase

Inferred from experiment

Subunit composition of evolved β-D-galactosidase = [EbgA]4[EbgC]4
         evolved β-D-galactosidase, α subunit; cryptic gene = EbgA
         evolved β-D-galactosidase, β subunit; cryptic gene = EbgC

The EbgA-EbgC complex represents the second β-D-galactosidase enzyme in E. coli. The wild-type enzyme is too catalytically feeble to allow growth on lactose as the sole carbon source. Spontaneous mutations that enable growth on lactose occur under selective conditions in the absence of LacZ [Campbell73a].

The ebg and lac operons are homologous and probably descended from a common ancestor [Stokes85, Stokes85a]. The EbgAC enzyme is a heterooctamer [Elliott92]. Catalytic activity of the large (EbgA) subunit alone suggests that the small subunit is associated with the optimal positioning of the electrophilic Mg2+ ions in the enzyme [Calugaru95]. Various types of evolved, catalytically active enzymes have been studied in detail [Elliott92, Hall89, Calugaru97].

Reviews: [Hall99a, Hall03a]

Created 05-Jan-2006 by Keseler I, SRI International
Last-Curated 05-Jan-2006 by Keseler I, SRI International

Sequence Features

Protein sequence of evolved beta-D-galactosidase, beta subunit; cryptic gene with features indicated

Feature Class Location Citations Comment
Pfam PF04074 3 -> 139
Inferred by computational analysis[Finn14]
DUF386 : Domain of unknown function (DUF386)
Sequence-Conflict 144 -> 149
Inferred by curator[Hall89, UniProt15]
UniProt: (in Ref. 1; AAA61972/CAA36275).

Gene Local Context (not to scale -- see Genome Browser for correct scale)

Gene local context diagram

Transcription Unit

Transcription-unit diagram


10/20/97 Gene b3077 from Blattner lab Genbank (v. M52) entry merged into EcoCyc gene EG10253; 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

Calugaru95: Calugaru SV, Hall BG, Sinnott ML (1995). "Catalysis by the large subunit of the second beta-galactosidase of Escherichia coli in the absence of the small subunit." Biochem J 312 ( Pt 1);281-6. PMID: 7492325

Calugaru97: Calugaru SV, Krishnan S, Chany CJ, Hall BG, Sinnott ML (1997). "Larger increases in sensitivity to paracatalytic inactivation than in catalytic competence during experimental evolution of the second beta-galactosidase of Escherichia coli." Biochem J 325 ( Pt 1);117-21. PMID: 9224636

Campbell73a: Campbell JH, Lengyel JA, Langridge J (1973). "Evolution of a second gene for beta-galactosidase in Escherichia coli." Proc Natl Acad Sci U S A 70(6);1841-5. PMID: 4124306

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

Elliott92: Elliott AC, K S, Sinnott ML, Smith PJ, Bommuswamy J, Guo Z, Hall BG, Zhang Y (1992). "The catalytic consequences of experimental evolution. Studies on the subunit structure of the second (ebg) beta-galactosidase of Escherichia coli, and on catalysis by ebgab, an experimental evolvant containing two amino acid substitutions." Biochem J 1992;282 ( Pt 1);155-64. PMID: 1540130

Finn14: Finn RD, Bateman A, Clements J, Coggill P, Eberhardt RY, Eddy SR, Heger A, Hetherington K, Holm L, Mistry J, Sonnhammer EL, Tate J, Punta M (2014). "Pfam: the protein families database." Nucleic Acids Res 42(Database issue);D222-30. PMID: 24288371

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

Hall03a: Hall BG (2003). "The EBG system of E. coli: origin and evolution of a novel beta-galactosidase for the metabolism of lactose." Genetica 118(2-3);143-56. PMID: 12868605

Hall89: Hall BG, Betts PW, Wootton JC (1989). "DNA sequence analysis of artificially evolved ebg enzyme and ebg repressor genes." Genetics 1989;123(4);635-48. PMID: 2515108

Hall99a: Hall BG (1999). "Experimental evolution of Ebg enzyme provides clues about the evolution of catalysis and to evolutionary potential." FEMS Microbiol Lett 174(1);1-8. PMID: 10234816

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

Stokes85: Stokes HW, Betts PW, Hall BG (1985). "Sequence of the ebgA gene of Escherichia coli: comparison with the lacZ gene." Mol Biol Evol 2(6);469-77. PMID: 3939707

Stokes85a: Stokes HW, Hall BG (1985). "Sequence of the ebgR gene of Escherichia coli: evidence that the EBG and LAC operons are descended from a common ancestor." Mol Biol Evol 1985;2(6);478-83. PMID: 3939708

UniProt15: UniProt Consortium (2015). "UniProt version 2015-08 released on 2015-07-22." Database.

Other References Related to Gene Regulation

Beisel11: Beisel CL, Storz G (2011). "The base-pairing RNA spot 42 participates in a multioutput feedforward loop to help enact catabolite repression in Escherichia coli." Mol Cell 41(3);286-97. PMID: 21292161

Huerta03: Huerta AM, Collado-Vides J (2003). "Sigma70 promoters in Escherichia coli: specific transcription in dense regions of overlapping promoter-like signals." J Mol Biol 333(2);261-78. PMID: 14529615

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 Pathway Tools version 19.5 (software by SRI International) on Thu May 5, 2016, biocyc14.