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O69315 (BGAL_THETH) Reviewed, UniProtKB/Swiss-Prot

Last modified June 11, 2014. Version 59. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data text xml rdf/xml gff fasta
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

Short name=Beta-gal
EC=3.2.1.23
Alternative name(s):
Lactase
OrganismThermus thermophilus
Taxonomic identifier274 [NCBI]
Taxonomic lineageBacteriaDeinococcus-ThermusDeinococciThermalesThermaceaeThermus

Protein attributes

Sequence length645 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Catalytic activity

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

Enzyme regulation

Inhibited by Cu2+ and Fe2+, and moderately activated by divalent cations such as Co2+, Mn2+ and Zn2+. Considerably activated by dithiothreitol, beta-mercaptoethanol and cysteine. Ref.1

Subunit structure

Homotrimer. Ref.1 Ref.2

Miscellaneous

The trimeric structure is essential to exhibit high enzymatic activity.

Sequence similarities

Belongs to the glycosyl hydrolase 42 family.

Biophysicochemical properties

Kinetic parameters:

KM=19 mM for lactose (at pH 6.5 and at 70 degrees Celsius) Ref.1

KM=5.9 mM for o-nitrophenyl beta-D-galactopyranoside (at pH 6.5 and at 70 degrees Celsius)

pH dependence:

Optimum pH is 6.5. No activity is detected at pH below 4.5.

Temperature dependence:

Optimum temperature is 70 degrees Celsius. It retains more than 75% of activity after incubation at 85 degrees Celsius and the half-life at 90 degrees Celsius is 1 hour. Thermostable.

Ontologies

Keywords
   LigandMetal-binding
Zinc
   Molecular functionGlycosidase
Hydrolase
   Technical term3D-structure
Direct protein sequencing
Gene Ontology (GO)
   Biological_processgalactose 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: UniProtKB-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 – 645645Beta-galactosidase
PRO_0000367028

Regions

Region360 – 3634Substrate binding

Sites

Active site1411Proton donor
Active site3121Nucleophile
Metal binding1061Zinc
Metal binding1501Zinc
Metal binding1521Zinc
Metal binding1551Zinc
Binding site1021Substrate
Binding site1401Substrate
Binding site3201Substrate

Secondary structure

.................................................................................................................. 645
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
O69315 [UniParc].

Last modified August 1, 1998. Version 1.
Checksum: 60FAE1EC1923C6C8

FASTA64572,824
        10         20         30         40         50         60 
MLGVCYYPEH WPKERWKEDA RRMREAGLSH VRIGEFAWAL LEPEPGRLEW GWLDEAIATL 

        70         80         90        100        110        120 
AAEGLKVVLG TPTATPPKWL VDRYPEILPV DREGRRRRFG GRRHYCFSSP VYREEARRIV 

       130        140        150        160        170        180 
TLLAERYGGL EAVAGFQTDN EYGCHDTVRC YCPRCQEAFR GWLEARYGTI EALNEAWGTA 

       190        200        210        220        230        240 
FWSQRYRSFA EVELPHLTVA EPNPSHLLDY YRFASDQVRA FNRLQVEILR AHAPGKFVTH 

       250        260        270        280        290        300 
NFMGFFTDLD AFALAQDLDF ASWDSYPLGF TDLMPLPPEE KLRYARTGHP DVAAFHHDLY 

       310        320        330        340        350        360 
RGVGRGRFWV MEQQPGPVNW APHNPSPAPG MVRLWTWEAL AHGAEVVSYF RWRQAPFAQE 

       370        380        390        400        410        420 
QMHAGLHRPD SAPDQGFFEA KRVAEELAAL ALPPVAQAPV ALVFDYEAAW IYEVQPQGAE 

       430        440        450        460        470        480 
WSYLGLVYLF YSALRRLGLD VDVVPPGASL RGYAFAVVPS LPIVREEALE AFREAEGPVL 

       490        500        510        520        530        540 
FGPRSGSKTE TFQIPKELPP GPLQALLPLK VVRVESLPPG LLEVAEGALG RFPLGLWREW 

       550        560        570        580        590        600 
VEAPLKPLLT FQDGKGALYR EGRYLYLAAW PSPELAGRLL SALAAEAGLK VLSLPEGLRL 

       610        620        630        640 
RRRGTWVFAF NYGPEAVEAP ASEGARFLLG SRRVGPYDLA VWEEA 

« Hide

References

[1]"Thermostable beta-galactosidase from an extreme thermophile, Thermus sp. A4: enzyme purification and characterization, and gene cloning and sequencing."
Ohtsu N., Motoshima H., Goto K., Tsukasaki F., Matsuzawa H.
Biosci. Biotechnol. Biochem. 62:1539-1545(1998) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-15, BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION, SUBUNIT.
Strain: A4.
[2]"Trimeric crystal structure of the glycoside hydrolase family 42 beta-galactosidase from Thermus thermophilus A4 and the structure of its complex with galactose."
Hidaka M., Fushinobu S., Ohtsu N., Motoshima H., Matsuzawa H., Shoun H., Wakagi T.
J. Mol. Biol. 322:79-91(2002) [PubMed] [Europe PMC] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS) IN COMPLEX WITH ZINC ION AND SUBSTRATE, REACTION MECHANISM, SUBUNIT.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
D85027 Genomic DNA. Translation: BAA28362.1.

3D structure databases

PDBe
RCSB-PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
1KWGX-ray1.60A1-645[»]
1KWKX-ray2.20A1-645[»]
ProteinModelPortalO69315.
SMRO69315. Positions 1-644.
ModBaseSearch...
MobiDBSearch...

Protein family/group databases

CAZyGH42. Glycoside Hydrolase Family 42.

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D2.60.40.1180. 1 hit.
3.20.20.80. 1 hit.
3.40.50.880. 1 hit.
InterProIPR013739. Beta_galactosidase_C.
IPR013738. Beta_galactosidase_Trimer.
IPR029062. Class_I_gatase-like.
IPR013780. Glyco_hydro_13_b.
IPR003476. Glyco_hydro_42.
IPR013529. Glyco_hydro_42_N.
IPR013781. Glyco_hydro_catalytic_dom.
IPR017853. Glycoside_hydrolase_SF.
[Graphical view]
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. SSF51445. 1 hit.
SSF52317. SSF52317. 1 hit.
ProtoNetSearch...

Other

EvolutionaryTraceO69315.

Entry information

Entry nameBGAL_THETH
AccessionPrimary (citable) accession number: O69315
Entry history
Integrated into UniProtKB/Swiss-Prot: March 24, 2009
Last sequence update: August 1, 1998
Last modified: June 11, 2014
This is version 59 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references

Glycosyl hydrolases

Classification of glycosyl hydrolase families and list of entries