Q9KI47 (BGAL_PLASS) Reviewed, UniProtKB/Swiss-Prot
Last modified October 16, 2013. Version 46. History...
Names and origin
|Sequence length||677 AA.|
|Protein existence||Evidence at protein level|
General annotation (Comments)
Hydrolyzes o-nitrophenyl-beta-D-galactopyranoside (ONPG), p-nitrophenyl-beta-D-galactopyranoside (PNPG), 5-bromo-4-chloro-3-indoyl-beta-D-galactosde (X-gal), o-nitrophenyl-beta-D-fucopyranoside (ONPF) and p-nitrophenyl-beta-D-fucopyranoside (PNPF) with greatest activity towards ONPG and PNPG and low levels of activity with ONPF and PNPF. Detectable, but very low levels of activity towards p-nitrophenyl-beta-lactose (PNPL), p-nitrophenyl-beta-cellobiose (PNPC), p-nitrophenyl-alpha-galactopyranoside (PNP-alpha-G), and p-nitrophenyl-beta-xylopyranoside (PNPX). Ref.1
Hydrolysis of terminal non-reducing beta-D-galactose residues in beta-D-galactosides. Ref.1
No activity is lost during treatment with 20 or 100 mM EDTA in Z buffer for 3 hours at 0 degrees Celsius, nor is activity greatly stimulated by the addition of cations. Inhibited by 1 mM zinc and 1 mM copper, the levels of activity decrease to 10% of the untreated control. Nickel, cobalt and manganese at concentrations of 10 mM decrease enzyme activity to either 40% (for nickel and cobalt) or 60% (for manganese) of the activity in untreated controls. No change in enzyme activity in the presence of calcium and magnesium at concentrations up to 50 mM. EDTA-treated enzyme exhibits a slight increase in relative specific activity when it is assayed in the presence of 50 mM NaCl or 50 mM KCl, it does not exhibit enhanced activity at concentrations greater than 250 mM. Maintains between 20 and 40% of activity in the presence of 4 M NaCl or 4 M KCl, and it is more active in the presence of KCl than in the presence of NaCl. Retains 50% of activity in the presence of 3 M KCl or 2.5 M NaCl. Ref.1
Possible reporter enzyme for halotolerant and halophilic organisms. May also be used in the food industry to digest plant polysaccharides in high-salt processes. Ref.1
Belongs to the glycosyl hydrolase 42 family.
KM=7.4 mM for ONPG (at 1.9 degrees Celsius and at pH 6.5) Ref.1
KM=4.5 mM for ONPG (at 10 degrees Celsius and at pH 6.5)
KM=5.4 mM for ONPG (at 20 degrees Celsius and at pH 6.5)
KM=5.0 mM for ONPG (at 30 degrees Celsius and at pH 6.5)
KM=4.9 mM for ONPG (at 39 degrees Celsius and at pH 6.5)
Vmax=63 µmol/min/mg enzyme with ONPG as substrate (at 1.9 degrees Celsius and pH 6.5)
Vmax=80 µmol/min/mg enzyme with ONPG as substrate (at 10 degrees Celsius and pH 6.5)
Vmax=223 µmol/min/mg enzyme with ONPG as substrate (at 20 degrees Celsius and pH 6.5)
Vmax=392 µmol/min/mg enzyme with ONPG as substrate (at 30 degrees Celsius and pH 6.5)
Vmax=467 µmol/min/mg enzyme with ONPG as substrate (at 39 degrees Celsius and pH 6.5)
Optimum pH is 6.5.
Optimum temperature is 42 degrees Celsius. Thermostable at temperatures at or below the optimal temperature for activity, but it is rapidly denatured at temperatures above 42 degrees Celsius. Irreversibly inactivated within 10 minutes at 55 degrees Celsius. Stable during storage at 5 degrees Celsius and loses no activity during storage for 4 months. Retains 10% of activity at 0 degrees Celsius.
|Technical term||Direct protein sequencing|
|Gene Ontology (GO)|
|Biological_process||galactose metabolic process|
Inferred from electronic annotation. Source: InterPro
Inferred from electronic annotation. Source: InterPro
Inferred from electronic annotation. Source: UniProtKB-ECmetal ion binding
Inferred from electronic annotation. Source: UniProtKB-KW
|Complete GO annotation...|
Sequence annotation (Features)
|Feature key||Position(s)||Length||Description||Graphical view||Feature identifier|
|Chain||1 – 677||677||Beta-galactosidase BgaA||PRO_0000407692|
|Region||357 – 360||4||Substrate binding|
|Active site||151||1||Proton donor By similarity|
|Active site||309||1||Nucleophile By similarity|
|Metal binding||116||1||Zinc By similarity|
|Metal binding||156||1||Zinc By similarity|
|Metal binding||158||1||Zinc By similarity|
|Metal binding||161||1||Zinc By similarity|
|Binding site||112||1||Substrate By similarity|
|Binding site||150||1||Substrate By similarity|
|Binding site||317||1||Substrate By similarity|
|||"Characterization of a salt-tolerant family 42 beta-galactosidase from a psychrophilic antarctic Planococcus isolate."|
Sheridan P.P., Brenchley J.E.
Appl. Environ. Microbiol. 66:2438-2444(2000) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], PROTEIN SEQUENCE OF 1-8, FUNCTION, CATALYTIC ACTIVITY, ENZYME REGULATION, BIOPHYSICOCHEMICAL PROPERTIES, SUBSTRATE SPECIFICITY, SUBUNIT, BIOTECHNOLOGY.
Strain: SOS Orange.
|AF242542 Genomic DNA. Translation: AAF75984.1.|
3D structure databases
Protein family/group databases
|CAZy||GH42. Glycoside Hydrolase Family 42. |
Protocols and materials databases
Enzyme and pathway databases
|BRENDA||220.127.116.11. 4880. |
Family and domain databases
|Gene3D||18.104.22.168. 1 hit. |
|InterPro||IPR013739. Beta_galactosidase_C. |
|Pfam||PF02449. Glyco_hydro_42. 1 hit. |
PF08533. Glyco_hydro_42C. 1 hit.
PF08532. Glyco_hydro_42M. 1 hit.
|PIRSF||PIRSF001084. B-galactosidase. 1 hit. |
|SUPFAM||SSF51445. SSF51445. 1 hit. |
|Accession||Primary (citable) accession number: Q9KI47|
|Entry status||Reviewed (UniProtKB/Swiss-Prot)|
|Annotation program||Prokaryotic Protein Annotation Program|