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Protein

Beta-galactosidase

Gene
N/A
Organism
Thermus thermophilus
Status
Reviewed-Annotation score: Annotation score: 5 out of 5-Experimental evidence at protein leveli

Functioni

Catalytic activityi

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

Enzyme regulationi

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.1 Publication

Kineticsi

  1. KM=19 mM for lactose (at pH 6.5 and at 70 degrees Celsius)1 Publication
  2. KM=5.9 mM for o-nitrophenyl beta-D-galactopyranoside (at pH 6.5 and at 70 degrees Celsius)1 Publication

    pH dependencei

    Optimum pH is 6.5. No activity is detected at pH below 4.5.1 Publication

    Temperature dependencei

    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.1 Publication

    Sites

    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Binding sitei102 – 1021Substrate1 Publication
    Metal bindingi106 – 1061Zinc
    Binding sitei140 – 1401Substrate1 Publication
    Active sitei141 – 1411Proton donor
    Metal bindingi150 – 1501Zinc
    Metal bindingi152 – 1521Zinc
    Metal bindingi155 – 1551Zinc
    Active sitei312 – 3121Nucleophile
    Binding sitei320 – 3201Substrate1 Publication

    GO - Molecular functioni

    GO - Biological processi

    Complete GO annotation...

    Keywords - Molecular functioni

    Glycosidase, Hydrolase

    Keywords - Ligandi

    Metal-binding, Zinc

    Protein family/group databases

    CAZyiGH42. Glycoside Hydrolase Family 42.

    Names & Taxonomyi

    Protein namesi
    Recommended name:
    Beta-galactosidase (EC:3.2.1.23)
    Short name:
    Beta-gal
    Alternative name(s):
    Lactase
    OrganismiThermus thermophilus
    Taxonomic identifieri274 [NCBI]
    Taxonomic lineageiBacteriaDeinococcus-ThermusDeinococciThermalesThermaceaeThermus

    Subcellular locationi

    GO - Cellular componenti

    Complete GO annotation...

    PTM / Processingi

    Molecule processing

    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Chaini1 – 645645Beta-galactosidasePRO_0000367028Add
    BLAST

    Interactioni

    Subunit structurei

    Homotrimer.2 Publications

    Structurei

    Secondary structure

    1
    645
    Legend: HelixTurnBeta strand
    Show more details
    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Beta strandi2 – 54Combined sources
    Helixi8 – 103Combined sources
    Helixi13 – 153Combined sources
    Helixi16 – 2611Combined sources
    Beta strandi30 – 334Combined sources
    Helixi38 – 414Combined sources
    Helixi51 – 6111Combined sources
    Turni62 – 643Combined sources
    Beta strandi66 – 705Combined sources
    Helixi78 – 836Combined sources
    Helixi85 – 873Combined sources
    Beta strandi99 – 1024Combined sources
    Helixi110 – 12718Combined sources
    Beta strandi133 – 1375Combined sources
    Beta strandi139 – 1413Combined sources
    Turni142 – 1465Combined sources
    Helixi153 – 16715Combined sources
    Helixi170 – 1778Combined sources
    Turni178 – 1803Combined sources
    Helixi181 – 1833Combined sources
    Helixi189 – 1913Combined sources
    Helixi204 – 23229Combined sources
    Beta strandi237 – 2393Combined sources
    Helixi251 – 2544Combined sources
    Helixi255 – 2573Combined sources
    Beta strandi258 – 2658Combined sources
    Helixi267 – 2737Combined sources
    Helixi278 – 2836Combined sources
    Turni284 – 2874Combined sources
    Helixi292 – 30312Combined sources
    Turni304 – 3063Combined sources
    Beta strandi308 – 3136Combined sources
    Beta strandi319 – 3235Combined sources
    Helixi331 – 34111Combined sources
    Beta strandi347 – 3504Combined sources
    Beta strandi356 – 3583Combined sources
    Turni359 – 3624Combined sources
    Helixi375 – 38814Combined sources
    Beta strandi399 – 4035Combined sources
    Helixi406 – 4149Combined sources
    Helixi423 – 43513Combined sources
    Turni436 – 4383Combined sources
    Beta strandi441 – 4444Combined sources
    Beta strandi454 – 4596Combined sources
    Helixi466 – 4738Combined sources
    Beta strandi479 – 4813Combined sources
    Turni483 – 4864Combined sources
    Helixi501 – 5055Combined sources
    Beta strandi510 – 5167Combined sources
    Beta strandi523 – 5275Combined sources
    Beta strandi530 – 5345Combined sources
    Beta strandi536 – 5427Combined sources
    Beta strandi548 – 5514Combined sources
    Beta strandi556 – 5616Combined sources
    Beta strandi564 – 5674Combined sources
    Helixi573 – 58614Combined sources
    Beta strandi598 – 6036Combined sources
    Beta strandi606 – 6116Combined sources
    Beta strandi613 – 6153Combined sources
    Beta strandi626 – 6305Combined sources
    Beta strandi632 – 6343Combined sources
    Beta strandi638 – 6436Combined sources

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    EntryMethodResolution (Å)ChainPositionsPDBsum
    1KWGX-ray1.60A1-645[»]
    1KWKX-ray2.20A1-645[»]
    ProteinModelPortaliO69315.
    SMRiO69315. Positions 1-644.
    ModBaseiSearch...
    MobiDBiSearch...

    Miscellaneous databases

    EvolutionaryTraceiO69315.

    Family & Domainsi

    Region

    Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifierActions
    Regioni360 – 3634Substrate binding

    Sequence similaritiesi

    Belongs to the glycosyl hydrolase 42 family.Curated

    Family and domain databases

    Gene3Di2.60.40.1180. 1 hit.
    3.20.20.80. 1 hit.
    3.40.50.880. 1 hit.
    InterProiIPR013739. 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]
    PfamiPF02449. Glyco_hydro_42. 1 hit.
    PF08533. Glyco_hydro_42C. 1 hit.
    PF08532. Glyco_hydro_42M. 1 hit.
    [Graphical view]
    PIRSFiPIRSF001084. B-galactosidase. 1 hit.
    SUPFAMiSSF51445. SSF51445. 1 hit.
    SSF52317. SSF52317. 1 hit.

    Sequencei

    Sequence statusi: Complete.

    O69315-1 [UniParc]FASTAAdd to basket

    « Hide

            10         20         30         40         50
    MLGVCYYPEH WPKERWKEDA RRMREAGLSH VRIGEFAWAL LEPEPGRLEW
    60 70 80 90 100
    GWLDEAIATL AAEGLKVVLG TPTATPPKWL VDRYPEILPV DREGRRRRFG
    110 120 130 140 150
    GRRHYCFSSP VYREEARRIV TLLAERYGGL EAVAGFQTDN EYGCHDTVRC
    160 170 180 190 200
    YCPRCQEAFR GWLEARYGTI EALNEAWGTA FWSQRYRSFA EVELPHLTVA
    210 220 230 240 250
    EPNPSHLLDY YRFASDQVRA FNRLQVEILR AHAPGKFVTH NFMGFFTDLD
    260 270 280 290 300
    AFALAQDLDF ASWDSYPLGF TDLMPLPPEE KLRYARTGHP DVAAFHHDLY
    310 320 330 340 350
    RGVGRGRFWV MEQQPGPVNW APHNPSPAPG MVRLWTWEAL AHGAEVVSYF
    360 370 380 390 400
    RWRQAPFAQE QMHAGLHRPD SAPDQGFFEA KRVAEELAAL ALPPVAQAPV
    410 420 430 440 450
    ALVFDYEAAW IYEVQPQGAE WSYLGLVYLF YSALRRLGLD VDVVPPGASL
    460 470 480 490 500
    RGYAFAVVPS LPIVREEALE AFREAEGPVL FGPRSGSKTE TFQIPKELPP
    510 520 530 540 550
    GPLQALLPLK VVRVESLPPG LLEVAEGALG RFPLGLWREW VEAPLKPLLT
    560 570 580 590 600
    FQDGKGALYR EGRYLYLAAW PSPELAGRLL SALAAEAGLK VLSLPEGLRL
    610 620 630 640
    RRRGTWVFAF NYGPEAVEAP ASEGARFLLG SRRVGPYDLA VWEEA
    Length:645
    Mass (Da):72,824
    Last modified:August 1, 1998 - v1
    Checksum:i60FAE1EC1923C6C8
    GO

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    D85027 Genomic DNA. Translation: BAA28362.1.

    Cross-referencesi

    Sequence databases

    Select the link destinations:
    EMBLi
    GenBanki
    DDBJi
    Links Updated
    D85027 Genomic DNA. Translation: BAA28362.1.

    3D structure databases

    Select the link destinations:
    PDBei
    RCSB PDBi
    PDBji
    Links Updated
    EntryMethodResolution (Å)ChainPositionsPDBsum
    1KWGX-ray1.60A1-645[»]
    1KWKX-ray2.20A1-645[»]
    ProteinModelPortaliO69315.
    SMRiO69315. Positions 1-644.
    ModBaseiSearch...
    MobiDBiSearch...

    Protein family/group databases

    CAZyiGH42. Glycoside Hydrolase Family 42.

    Protocols and materials databases

    Structural Biology KnowledgebaseSearch...

    Miscellaneous databases

    EvolutionaryTraceiO69315.

    Family and domain databases

    Gene3Di2.60.40.1180. 1 hit.
    3.20.20.80. 1 hit.
    3.40.50.880. 1 hit.
    InterProiIPR013739. 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]
    PfamiPF02449. Glyco_hydro_42. 1 hit.
    PF08533. Glyco_hydro_42C. 1 hit.
    PF08532. Glyco_hydro_42M. 1 hit.
    [Graphical view]
    PIRSFiPIRSF001084. B-galactosidase. 1 hit.
    SUPFAMiSSF51445. SSF51445. 1 hit.
    SSF52317. SSF52317. 1 hit.
    ProtoNetiSearch...

    Publicationsi

    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.

    Entry informationi

    Entry nameiBGAL_THETH
    AccessioniPrimary (citable) accession number: O69315
    Entry historyi
    Integrated into UniProtKB/Swiss-Prot: March 24, 2009
    Last sequence update: August 1, 1998
    Last modified: May 27, 2015
    This is version 63 of the entry and version 1 of the sequence. [Complete history]
    Entry statusiReviewed (UniProtKB/Swiss-Prot)
    Annotation programProkaryotic Protein Annotation Program

    Miscellaneousi

    Miscellaneous

    The trimeric structure is essential to exhibit high enzymatic activity.

    Keywords - Technical termi

    3D-structure, Direct protein sequencing

    Documents

    1. Glycosyl hydrolases
      Classification of glycosyl hydrolase families and list of entries
    2. PDB cross-references
      Index of Protein Data Bank (PDB) cross-references
    3. SIMILARITY comments
      Index of protein domains and families

    External Data

    Dasty 3

    Similar proteinsi

    Links to similar proteins from the UniProt Reference Clusters (UniRef) at 100%, 90% and 50% sequence identity:
    100%UniRef100 combines identical sequences and sub-fragments with 11 or more residues from any organism into Uniref entry.
    90%UniRef90 is built by clustering UniRef100 sequences that have at least 90% sequence identity to, and 80% overlap with, the longest sequence (a.k.a seed sequence).
    50%UniRef50 is built by clustering UniRef90 seed sequences that have at least 50% sequence identity to, and 80% overlap with, the longest sequence in the cluster.