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P19668 (BGAL_GEOKU) Reviewed, UniProtKB/Swiss-Prot

Last modified December 14, 2011. Version 65. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
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to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Beta-galactosidase bgaB
Short name=Beta-gal
EC=3.2.1.23
Alternative name(s):
Beta-galactosidase I
Lactase
Gene names
Name:bgaB
OrganismGeobacillus kaustophilus
Taxonomic identifier1462 [NCBI]
Taxonomic lineageBacteria › Firmicutes › Bacillales › Bacillaceae › Geobacillus

Protein attributes

Sequence length672 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Hydrolyzes 6-bromo-2-naphthyl-beta-D-galactopyranoside and o-nitrophenyl-beta-D-galactopyranoside (ONPG). Possesses a high level of transgalactosylation activity. Hydrolyzes lactose in milk. Ref.3

Catalytic activity

Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides. Ref.2 Ref.3

Enzyme regulation

By divalent metal ions. Fe2+, Zn2+, Cu2+, Pb2+ and Sn2+ inhibit 52, 76.6, 85.3, 100 and 100% of the enzyme acitivity, respectively. Other metal cations and EDTA do not inhibit this enzyme. Thiol reagents 2-mercaptoethanol and dithiothreitol have no effect on the activity. Sulfhydryl group-blocking reagents p-chloromercuribenzoic acid and iodoacetic acid inhibit 86.2 and 74% of the enzyme activity, respectively. Ref.3

Biotechnological use

Has potential for enzyme application in low-lactose milk production during milk pasteurization. Ref.3

Sequence similarities

Belongs to the glycosyl hydrolase 42 family.

Biophysicochemical properties

Kinetic parameters:

KM=2.96 mM for ONPG (at 55 degrees Celsius and pH 7.0) Ref.1 Ref.3

Vmax=6.62 µmol/min/mg enzyme with ONPG as substrate (at 55 degrees Celsius and pH 7.0)

pH dependence:

Optimum pH is 7.0. Retains more than 80% of the activity at a pH range of 6.0-7.5.

Temperature dependence:

Optimum temperature for the activity is 70 degrees Celsius using ONPG as substrate. Stable up to 70 degrees Celsius (Ref.1). Retains 80% of the activity at 75 degrees Celsius (Ref.3). Kinetics of thermal inactivation and half-life times at 60, 65 and 70 degrees Celsius are 120, 50 and 9 hours, respectively.

Ontologies

Keywords
   LigandMetal-binding
Zinc
   Molecular functionGlycosidase
Hydrolase
   Technical termDirect protein sequencing
Gene Ontology (GO)
   Biological processcarbohydrate metabolic process

Inferred from electronic annotation. Source: InterPro

   Cellular componentbeta-galactosidase complex

Inferred from electronic annotation. Source: InterPro

   Molecular functionbeta-galactosidase activity

Inferred from electronic annotation. Source: EC

metal ion binding

Inferred from electronic annotation. Source: UniProtKB-KW

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 672672Beta-galactosidase bgaB
PRO_0000057691

Regions

Region351 – 3544Substrate binding

Sites

Active site1481Proton donor By similarity
Active site3031Nucleophile By similarity
Metal binding1131Zinc By similarity
Metal binding1561Zinc By similarity
Metal binding1581Zinc By similarity
Metal binding1611Zinc By similarity
Binding site1091Substrate By similarity
Binding site1471Substrate By similarity
Binding site3111Substrate By similarity

Sequences

Sequence LengthMass (Da)Tools
P19668 [UniParc].

Last modified February 1, 1991. Version 1.
Checksum: FF611FFBEF68F09A

FASTA67278,053
        10         20         30         40         50         60 
MNVLSSICYG GDYNPEQWPE EIWYEDAKLM QKAGVNLVSL GIFSWSKIEP SDGVFDFEWL 

        70         80         90        100        110        120 
DKVIDILYDH GVYINLGTAT ATTPAWFVKK YPDSLPIDES GVILSFGSRQ HYCPNHPQLI 

       130        140        150        160        170        180 
THIKRLVRAI AERYKNHPAL KMWHVNNEYA CHVSKCFCEN CAVAFRKWLK ERYKTIDELN 

       190        200        210        220        230        240 
ERWGTNFWGQ RYNHWDEINP PRKAPTFINP SQELDYYRFM NDSILKLFLT EKEILREVTP 

       250        260        270        280        290        300 
DIPVSTNFMG SFKPLNYFQW AQHVDIVTWD SYPDPREGLP IQHAMMNDLM RSLRKGQPFI 

       310        320        330        340        350        360 
LMEQVTSHVN WRDINVPKPP GVMRLWSYAT IARGADGIMF FQWRQSRAGA EKFHGAMVPH 

       370        380        390        400        410        420 
FLNENNRIYR EVTQLGQELK KLDCLVGSRI KAEVAIIFDW ENWWAVELSS KPHNKLRYIP 

       430        440        450        460        470        480 
IVEAYYRELY KRNIAVDFVR PSDDLTKYKV VIAPMLYMVK EGEDENLRQF VANGGTLIVS 

       490        500        510        520        530        540 
FFSGIVDEND RVHLGGYPGP LRDILGIFVE EFVPYPETKV NKIYSNDGEY DCTTWADIIR 

       550        560        570        580        590        600 
LEGAEPLATF KGDWYAGLPA VTRNCYGKGE GIYVGTYPDS NYLGRLLEQV FAKHHINPIL 

       610        620        630        640        650        660 
EVAENVEVQQ RETDEWKYLI IINHNDYEVT LSLPEDKIYQ NMIDGKCFRG GELRIQGVDV 

       670 
AVLREHDEAG KV

« Hide

References

[1]"Structure of a beta-galactosidase gene of Bacillus stearothermophilus."
Hirata H., Fukazawa T., Negoro S., Okada H.
J. Bacteriol. 166:722-727(1986) [PubMed: 3086288] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-14, BIOPHYSICOCHEMICAL PROPERTIES.
Strain: ATCC 8005 / DSM 7263 / JCM 20319 / NCIMB 8547 / NRRL NRS-81 / IAM 11001.
[2]"Molecular basis of isozyme formation of beta-galactosidases in Bacillus stearothermophilus: isolation of two beta-galactosidase genes, bgaA and bgaB."
Hirata H., Negoro S., Okada H.
J. Bacteriol. 160:9-14(1984) [PubMed: 6434528] [Abstract]
Cited for: CATALYTIC ACTIVITY.
Strain: ATCC 8005 / DSM 7263 / JCM 20319 / NCIMB 8547 / NRRL NRS-81 / IAM 11001.
[3]"Production, purification, and characterization of a potential thermostable galactosidase for milk lactose hydrolysis from Bacillus stearothermophilus."
Chen W., Chen H., Xia Y., Zhao J., Tian F., Zhang H.
J. Dairy Sci. 91:1751-1758(2008) [PubMed: 18420605] [Abstract]
Cited for: FUNCTION, CATALYTIC ACTIVITY, BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION, BIOTECHNOLOGY.
Strain: ATCC 8005 / DSM 7263 / JCM 20319 / NCIMB 8547 / NRRL NRS-81 / IAM 11001.
+Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ		M13466 Genomic DNA. Translation: AAA22262.1.
PIRA29836.

3D structure databases

ProteinModelPortalP19668.
ModBaseSearch...

Protein family/group databases

CAZyGH42. Glycoside Hydrolase Family 42.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

InterProIPR013739. Beta_galactosidase_C.
IPR013738. Beta_galactosidase_Trimer.
IPR003476. Glyco_hydro_42.
IPR013529. Glyco_hydro_42_N.
IPR013781. Glyco_hydro_subgr_catalytic.
IPR017853. Glycoside_hydrolase_SF.
[Graphical view]
Gene3DG3DSA:3.20.20.80. Glyco_hydro_cat. 1 hit.
PfamPF02449. Glyco_hydro_42. 1 hit.
PF08533. Glyco_hydro_42C. 1 hit.
PF08532. Glyco_hydro_42M. 1 hit.
[Graphical view]
PIRSFPIRSF001084. B-galactosidase. 1 hit.
SUPFAMSSF51445. Glyco_hydro_cat. 1 hit.
ProtoNetSearch...

Entry information

Entry nameBGAL_GEOKU
AccessionPrimary (citable) accession number: P19668
Entry history
Integrated into UniProtKB/Swiss-Prot: February 1, 1991
Last sequence update: February 1, 1991
Last modified: December 14, 2011
This is version 65 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Relevant documents

Glycosyl hydrolases

Classification of glycosyl hydrolase families and list of entries

SIMILARITY comments

Index of protein domains and families

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