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Protein

Beta-galactosidase bgaB

Gene

bgaB

Organism
Geobacillus kaustophilus
Status
Reviewed-Annotation score: Annotation score: 4 out of 5-Experimental evidence at protein leveli

Functioni

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.1 Publication

Catalytic activityi

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

Enzyme regulationi

By divalent metal ions. Fe2+, Zn2+, Cu2+, Pb2+ and Sn2+ inhibit 52, 76.6, 85.3, 100 and 100% of the enzyme activity, 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.1 Publication

Kineticsi

  1. KM=2.96 mM for ONPG (at 55 degrees Celsius and pH 7.0)2 Publications
  1. Vmax=6.62 µmol/min/mg enzyme with ONPG as substrate (at 55 degrees Celsius and pH 7.0)2 Publications

pH dependencei

Optimum pH is 7.0. Retains more than 80% of the activity at a pH range of 6.0-7.5.2 Publications

Temperature dependencei

Optimum temperature for the activity is 70 degrees Celsius using ONPG as substrate. Stable up to 70 degrees Celsius (PubMed:3086288). Retains 80% of the activity at 75 degrees Celsius (PubMed:18420605). Kinetics of thermal inactivation and half-life times at 60, 65 and 70 degrees Celsius are 120, 50 and 9 hours, respectively.2 Publications

Sites

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Binding sitei109SubstrateBy similarity1
Metal bindingi113ZincBy similarity1
Binding sitei147SubstrateBy similarity1
Active sitei148Proton donorBy similarity1
Metal bindingi156ZincBy similarity1
Metal bindingi158ZincBy similarity1
Metal bindingi161ZincBy similarity1
Active sitei303NucleophileBy similarity1
Binding sitei311SubstrateBy similarity1

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 bgaB (EC:3.2.1.23)
Short name:
Beta-gal
Alternative name(s):
Beta-galactosidase I
Lactase
Gene namesi
Name:bgaB
OrganismiGeobacillus kaustophilus
Taxonomic identifieri1462 [NCBI]
Taxonomic lineageiBacteriaFirmicutesBacilliBacillalesBacillaceaeGeobacillus

Subcellular locationi

GO - Cellular componenti

Complete GO annotation...

Pathology & Biotechi

Biotechnological usei

Has potential for enzyme application in low-lactose milk production during milk pasteurization.1 Publication

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
ChainiPRO_00000576911 – 672Beta-galactosidase bgaBAdd BLAST672

Structurei

3D structure databases

ProteinModelPortaliP19668.
ModBaseiSearch...
MobiDBiSearch...

Family & Domainsi

Region

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Regioni351 – 354Substrate binding4

Sequence similaritiesi

Belongs to the glycosyl hydrolase 42 family.Curated

Family and domain databases

Gene3Di3.20.20.80. 1 hit.
3.40.50.880. 1 hit.
InterProiIPR013739. Beta_galactosidase_C.
IPR013738. Beta_galactosidase_Trimer.
IPR029062. Class_I_gatase-like.
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.

P19668-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MNVLSSICYG GDYNPEQWPE EIWYEDAKLM QKAGVNLVSL GIFSWSKIEP
60 70 80 90 100
SDGVFDFEWL DKVIDILYDH GVYINLGTAT ATTPAWFVKK YPDSLPIDES
110 120 130 140 150
GVILSFGSRQ HYCPNHPQLI THIKRLVRAI AERYKNHPAL KMWHVNNEYA
160 170 180 190 200
CHVSKCFCEN CAVAFRKWLK ERYKTIDELN ERWGTNFWGQ RYNHWDEINP
210 220 230 240 250
PRKAPTFINP SQELDYYRFM NDSILKLFLT EKEILREVTP DIPVSTNFMG
260 270 280 290 300
SFKPLNYFQW AQHVDIVTWD SYPDPREGLP IQHAMMNDLM RSLRKGQPFI
310 320 330 340 350
LMEQVTSHVN WRDINVPKPP GVMRLWSYAT IARGADGIMF FQWRQSRAGA
360 370 380 390 400
EKFHGAMVPH FLNENNRIYR EVTQLGQELK KLDCLVGSRI KAEVAIIFDW
410 420 430 440 450
ENWWAVELSS KPHNKLRYIP IVEAYYRELY KRNIAVDFVR PSDDLTKYKV
460 470 480 490 500
VIAPMLYMVK EGEDENLRQF VANGGTLIVS FFSGIVDEND RVHLGGYPGP
510 520 530 540 550
LRDILGIFVE EFVPYPETKV NKIYSNDGEY DCTTWADIIR LEGAEPLATF
560 570 580 590 600
KGDWYAGLPA VTRNCYGKGE GIYVGTYPDS NYLGRLLEQV FAKHHINPIL
610 620 630 640 650
EVAENVEVQQ RETDEWKYLI IINHNDYEVT LSLPEDKIYQ NMIDGKCFRG
660 670
GELRIQGVDV AVLREHDEAG KV
Length:672
Mass (Da):78,053
Last modified:February 1, 1991 - v1
Checksum:iFF611FFBEF68F09A
GO

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M13466 Genomic DNA. Translation: AAA22262.1.
PIRiA29836.

Cross-referencesi

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
M13466 Genomic DNA. Translation: AAA22262.1.
PIRiA29836.

3D structure databases

ProteinModelPortaliP19668.
ModBaseiSearch...
MobiDBiSearch...

Protein family/group databases

CAZyiGH42. Glycoside Hydrolase Family 42.

Protocols and materials databases

Structural Biology KnowledgebaseSearch...

Family and domain databases

Gene3Di3.20.20.80. 1 hit.
3.40.50.880. 1 hit.
InterProiIPR013739. Beta_galactosidase_C.
IPR013738. Beta_galactosidase_Trimer.
IPR029062. Class_I_gatase-like.
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...

Entry informationi

Entry nameiBGAL_GEOKU
AccessioniPrimary (citable) accession number: P19668
Entry historyi
Integrated into UniProtKB/Swiss-Prot: February 1, 1991
Last sequence update: February 1, 1991
Last modified: October 1, 2014
This is version 75 of the entry and version 1 of the sequence. [Complete history]
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programProkaryotic Protein Annotation Program

Miscellaneousi

Keywords - Technical termi

Direct protein sequencing

Documents

  1. Glycosyl hydrolases
    Classification of glycosyl hydrolase families and list of entries
  2. SIMILARITY comments
    Index of protein domains and families

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 one 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.