Reviewed, UniProtKB/Swiss-Prot P06864 (BGA2_ECOLI)

Names and origin

Protein names

Recommended name:
    Evolved beta-galactosidase subunit alpha
      Short name=Beta-gal
    EC=3.2.1.23
Alternative name(s):
    Lactase

Gene names

Name:	ebgA
Ordered Locus Names:	b3076, JW5511

Organism

Escherichia coli (strain K12) [Complete proteome] [HAMAP]

Taxonomic identifier

83333 [NCBI]

Taxonomic lineage

Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacteriales › Enterobacteriaceae › Escherichia

Protein attributes

Sequence length	1030 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	The wild-type enzyme is an ineffective lactase. Two classes of point mutations dramatically improve activity of the enzyme.
Catalytic activity	Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides.
Subunit structure	Heterooctamer of 4 alpha and 4 beta subunits. Ref.7
Sequence similarities	Belongs to the glycosyl hydrolase 2 family.

Ontologies

Keywords
Molecular function	Glycosidase Hydrolase
Technical term	Complete proteome
Gene Ontology (GO)
Biological process	carbohydrate metabolic process Inferred from electronic annotation. Source: InterPro
Cellular component	beta-galactosidase complex Inferred from electronic annotation. Source: InterPro
Molecular function	beta-galactosidase activity Inferred from electronic annotation. Source: EC carbohydrate binding Inferred from electronic annotation. Source: InterPro cation binding Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Chain	1 – 1030	1030	Evolved beta-galactosidase subunit alpha		PRO_0000057651
Sites
	Active site	449	1	Proton donor Ref.6
	Active site	512	1	Nucleophile By similarity
Natural variations
	Natural variant	92	1	D → N Improve activity.
	Natural variant	93	1	E → K Improve activity.
	Natural variant	976	1	W → C Improve activity.
	Natural variant	978	1	S → G Improve activity.
Experimental info
	Sequence conflict	275	1	S → T Ref.1
	Sequence conflict	275	1	S → T Ref.2
	Sequence conflict	275	1	S → T in AAA57877. Ref.3
	Sequence conflict	465	1	A → R Ref.1
	Sequence conflict	465	1	A → R Ref.2
	Sequence conflict	640	1	T → S Ref.1
	Sequence conflict	640	1	T → S Ref.2
	Sequence conflict	649	1	R → P Ref.1
	Sequence conflict	649	1	R → P Ref.2
	Sequence conflict	767	1	M → MM Ref.1
	Sequence conflict	767	1	M → MM Ref.2
	Sequence conflict	891 – 892	2	ST → QA Ref.1
	Sequence conflict	891 – 892	2	ST → QA Ref.2
	Sequence conflict	891 – 892	2	ST → QA in AAA57877. Ref.3
	Sequence conflict	1026	1	S → T Ref.1
	Sequence conflict	1026	1	S → T Ref.2

Sequences

	Sequence		Length	Mass (Da)
	P06864-1 [UniParc]. Last modified October 11, 2004. Version 4. Checksum: FEC4D7A558C6EE94	FASTA	1,030	117,879
	10 20 30 40 50 60 MNRWENIQLT HENRLAPRAY FFSYDSVAQA RTFARETSSL FLPLSGQWNF HFFDHPLQVP 70 80 90 100 110 120 EAFTSELMAD WGHITVPAMW QMEGHGKLQY TDEGFPFPID VPFVPSDNPT GAYQRIFTLS 130 140 150 160 170 180 DGWQGKQTLI KFDGVETYFE VYVNGQYVGF SKGSRLTAEF DISAMVKTGD NLLCVRVMQW 190 200 210 220 230 240 ADSTYVEDQD MWWSAGIFRD VYLVGKHLTH INDFTVRTDF DEAYCDATLS CEVVLENLAA 250 260 270 280 290 300 SPVVTTLEYT LFDGERVVHS SAIDHLAIEK LTSASFAFTV EQPQQWSAES PYLYHLVMTL 310 320 330 340 350 360 KDANGNVLEV VPQRVGFRDI KVRDGLFWIN NRYVMLHGVN RHDNDHRKGR AVGMDRVEKD 370 380 390 400 410 420 LQLMKQHNIN SVRTAHYPND PRFYELCDIY GLFVMAETDV ESHGFANVGD ISRITDDPQW 430 440 450 460 470 480 EKVYVERIVR HIHAQKNHPS IIIWSLGNES GYGCNIRAMY HAAKALDDTR LVHYEEDRDA 490 500 510 520 530 540 EVVDIISTMY TRVPLMNEFG EYPHPKPRII CEYAHAMGNG PGGLTEYQNV FYKHDCIQGH 550 560 570 580 590 600 YVWEWCDHGI QAQDDHGNVW YKFGGDYGDY PNNYNFCLDG LIYSDQTPGP GLKEYKQVIA 610 620 630 640 650 660 PVKIHARDLT RGELKVENKL WFTTLDDYTL HAEVRAEGET LATQQIKLRD VAPNSEAPLQ 670 680 690 700 710 720 ITLPQLDARE AFLNITVTKD SRTRYSEAGH PIATYQFPLK ENTAQPVPFA PNNARPLTLE 730 740 750 760 770 780 DDRLSCTVRG YNFAITFSKM SGKPTSWQVN GESLLTREPK INFFKPMIDN HKQEYEGLWQ 790 800 810 820 830 840 PNHLQIMQEH LRDFAVEQSD GEVLIISRTV IAPPVFDFGM RCTYIWRIAA DGQVNVALSG 850 860 870 880 890 900 ERYGDYPHII PCIGFTMGIN GEYDQVAYYG RGPGENYADS QQANIIDIWR STVDAMFENY 910 920 930 940 950 960 PFPQNNGNRQ HVRWTALTNR HGNGLLVVPQ RPINFSAWHY TQENIHAAQH CNELQRSDDI 970 980 990 1000 1010 1020 TLNLDHQLLG LGSNSWGSEV LDSWRVWFRD FSYGFTLLPV SGGEATAQSL ASYEFGAGFF 1030 STNLHSENKQ

References

	« Hide 'large scale' referencesShow 'large scale' references »
[1]	"DNA sequence analysis of artificially evolved ebg enzyme and ebg repressor genes." Hall B.G., Betts P.W., Wootton J.C. Genetics 123:635-648(1989) [PubMed: 2515108] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[2]	"Sequence of the ebgA gene of Escherichia coli: comparison with the lacZ gene." Stokes H.W., Betts P.W., Hall B.G. Mol. Biol. Evol. 2:469-477(1985) [PubMed: 3939707] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
[3]	"The complete genome sequence of Escherichia coli K-12." Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y. Science 277:1453-1474(1997) [PubMed: 9278503] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / MG1655 / ATCC 47076.
[4]	"Escherichia coli K-12: a cooperatively developed annotation snapshot -- 2005." Riley M., Abe T., Arnaud M.B., Berlyn M.K.B., Blattner F.R., Chaudhuri R.R., Glasner J.D., Horiuchi T., Keseler I.M., Kosuge T., Mori H., Perna N.T., Plunkett G. III, Rudd K.E., Serres M.H., Thomas G.H., Thomson N.R., Wishart D., Wanner B.L. Nucleic Acids Res. 34:1-9(2006) [PubMed: 16397293] [Abstract] Cited for: SEQUENCE REVISION TO 275 AND 891-892.
[5]	"Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110." Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T. Mol. Syst. Biol. 2:E1-E5(2006) [PubMed: 16738553] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[6]	"The active site regions of lacZ and ebg beta-galactosidases are homologous." Fowler A.V., Smith P.J. J. Biol. Chem. 258:10204-10207(1983) [PubMed: 6411710] [Abstract] Cited for: ACTIVE SITE REGIONS.
[7]	"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." Elliott A.C., Sinnott M.L., Smith P.J., Bommuswamy J., Guo Z., Hall B.G., Zhang Y. Biochem. J. 282:155-164(1992) [PubMed: 1540130] [Abstract] Cited for: SUBUNIT.

Cross-references

Sequence databases
EMBLGenBankDDBJ	M64441 Genomic DNA. Translation: AAA61971.1. X52031 Genomic DNA. Translation: CAA36274.1. X03228 Genomic DNA. Translation: CAA26977.1. Sequence problems. U18997 Genomic DNA. Translation: AAA57877.1. Different initiation. U00096 Genomic DNA. Translation: AAT48164.1. AP009048 Genomic DNA. Translation: BAE77126.1.
PIR	GBECE. A65096.
RefSeq	AP_003625.1. YP_026199.1.
3D structure databases
HSSP	HSSP built from PDB template 1JZ8 based on UniProtKB P00722.
ModBase	Search...
Protein-protein interaction databases
DIP	DIP:2893N.
STRING	P06864.
Protein family/group databases
CAZy	GH2. Glycoside Hydrolase Family 2.
Genome annotation databases
GeneID	947583.
GenomeReviews	Gene locus JW5511 in contig AP009048_GR. Gene locus b3076 in contig U00096_GR.
KEGG	ecj:JW5511. eco:b3076.
Organism-specific databases
EchoBASE	EB0248.
EcoGene	EG10252. ebgA.
CMR	Search...
Phylogenomic databases
HOGENOM	P06864.
OMA	KIHALDL.
Enzyme and pathway databases
BioCyc	EcoCyc:EG10252-MON.
Gene expression databases
Genevestigator	P06864.
Family and domain databases
InterPro	IPR014718. Glyco_hydro-type_carb-bd_sub. IPR006101. Glyco_hydro_2. IPR013812. Glyco_hydro_2/20_Ig-like. IPR006104. Glyco_hydro_2_carb-bd. IPR006102. Glyco_hydro_2_Ig-like. IPR006103. Glyco_hydro_2_TIM. IPR004199. Glyco_hydro_42_D5. IPR013781. Glyco_hydro_sg_catalytic. [Graphical view]
Gene3D	G3DSA:2.60.40.320. Glyco_hydro_2/20_Ig-like. 2 hits. G3DSA:2.70.98.10. Glyco_hydro_42_D5. 1 hit. G3DSA:3.20.20.80. Glyco_hydro_cat. 1 hit.
Pfam	PF02929. Bgal_small_N. 1 hit. PF00703. Glyco_hydro_2. 1 hit. PF02836. Glyco_hydro_2_C. 1 hit. PF02837. Glyco_hydro_2_N. 1 hit. [Graphical view]
PRINTS	PR00132. GLHYDRLASE2.
PROSITE	PS00719. GLYCOSYL_HYDROL_F2_1. 1 hit. PS00608. GLYCOSYL_HYDROL_F2_2. 1 hit. [Graphical view]
ProtoNet	Search...
Other Resources
DrugBank	DB00581. Lactulose.

Entry information

Entry name

BGA2_ECOLI

Accession

Primary (citable) accession number: P06864
Secondary accession number(s): P76660, Q2M9D0, Q6BF50

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 1, 1988
Last sequence update:	October 11, 2004
Last modified:	November 3, 2009
This is version 96 of the entry and version 4 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

HAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)