Q9KK62 · CBH_BIFLN
- ProteinBile salt hydrolase/transferase
- Genebsh
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids317 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Possesses dual functions in bile acid metabolism (By similarity).
Acts as a bile salt hydrolase that catalyzes the deconjugation of glycine- and taurine-linked bile salts, which occurs naturally in the intestines of humans, releasing amino acid residues and deconjugated bile salts (bile acids). Can hydrolyze the amide bond in all six major human conjugated bile salts, namely glycocholate (GCA), glycodeoxycholate (GDCA), glycochenodeoxycholate (GCDCA), taurocholate (TCA), taurodeoxycholate (TDCA) and taurochenodeoxycholate (TCDCA). Shows a slight preference for glycine-conjugated bile acids as substrates (PubMed:10831430, PubMed:16905539).
Also acts as an amine N-acyltransferase that conjugates a wide variety of amino acids to conjugated and non-conjugated bile acids, thus producing bacterial bile acid amidates (BBAAs) - also named microbially conjugated bile acids (MCBAs) - in the gastrointestinal tract. These BBAAs may facilitate communication between the microbiota and host through the activation of human ligand-activated transcription factors (By similarity).
Is totally inactive toward penicillin V (PubMed:16905539).
Acts as a bile salt hydrolase that catalyzes the deconjugation of glycine- and taurine-linked bile salts, which occurs naturally in the intestines of humans, releasing amino acid residues and deconjugated bile salts (bile acids). Can hydrolyze the amide bond in all six major human conjugated bile salts, namely glycocholate (GCA), glycodeoxycholate (GDCA), glycochenodeoxycholate (GCDCA), taurocholate (TCA), taurodeoxycholate (TDCA) and taurochenodeoxycholate (TCDCA). Shows a slight preference for glycine-conjugated bile acids as substrates (PubMed:10831430, PubMed:16905539).
Also acts as an amine N-acyltransferase that conjugates a wide variety of amino acids to conjugated and non-conjugated bile acids, thus producing bacterial bile acid amidates (BBAAs) - also named microbially conjugated bile acids (MCBAs) - in the gastrointestinal tract. These BBAAs may facilitate communication between the microbiota and host through the activation of human ligand-activated transcription factors (By similarity).
Is totally inactive toward penicillin V (PubMed:16905539).
Catalytic activity
- glycocholate + H2O = cholate + glycineThis reaction proceeds in the forward direction.
- glycodeoxycholate + H2O = deoxycholate + glycineThis reaction proceeds in the forward direction.
- chenodeoxycholate + glycine = glycochenodeoxycholate + H2OThis reaction proceeds in the backward direction.
- cholate + taurine = H2O + taurocholateThis reaction proceeds in the backward direction.
- H2O + taurodeoxycholate = deoxycholate + taurineThis reaction proceeds in the forward direction.
- an L-alpha-amino acid + cholate = an N-choloyl-L-alpha-amino acid + H2OThis reaction proceeds in the forward direction.
- an L-alpha-amino acid + taurocholate = an N-choloyl-L-alpha-amino acid + taurineThis reaction proceeds in the forward direction.
- cholate + L-alanine = H2O + L-alanocholateThis reaction proceeds in the forward direction.
- L-alanine + taurocholate = L-alanocholate + taurineThis reaction proceeds in the forward direction.
- cholate + L-serine = H2O + L-serocholateThis reaction proceeds in the forward direction.
- L-serine + taurocholate = L-serocholate + taurineThis reaction proceeds in the forward direction.
- cholate + L-histidine = H2O + L-histidocholateThis reaction proceeds in the forward direction.
- L-histidine + taurocholate = L-histidocholate + taurineThis reaction proceeds in the forward direction.
Activity regulation
Hydrolase activity is competitively inhibited by the products cholate (CA) and deoxycholate (DCA), and by phenylacetate and 4-aminophenylacetate. Penicillin V and penicillin G show mixed inhibition (PubMed:16905539).
Strongly inhibited by thiol enzyme inhibitors in vitro (PubMed:10831430).
Strongly inhibited by thiol enzyme inhibitors in vitro (PubMed:10831430).
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
0.16 mM | glycocholate | 5.5 | 37 | |||
0.28 mM | glycodeoxycholate | 5.5 | 37 | |||
0.13 mM | glycochenodeoxycholate | 5.5 | 37 | |||
1.12 mM | taurocholate | 5.5 | 37 | |||
0.79 mM | taurodeoxycholate | 5.5 | 37 | |||
0.33 mM | taurochenodeoxycholate | 5.5 | 37 | |||
0.22 mM | glycocholate | 6.5 | 40 | |||
0.18 mM | glycodeoxycholate | 6.5 | 40 | |||
0.28 mM | glycochenodeoxycholate | 6.5 | 40 | |||
0.32 mM | taurocholate | 6.5 | 40 | |||
0.49 mM | taurodeoxycholate | 6.5 | 40 | |||
0.42 mM | taurochenodeoxycholate | 6.5 | 40 |
kcat is 85 sec-1 with glycocholate as substrate. kcat is 76 sec-1 with taurocholate as substrate (at 40 degrees Celsius and pH 6.5).
pH Dependence
Optimum pH is 6 for the hydrolase activity. Highly active in the pH range 5-7. Is stable at pH values from 4 to 8. At pH values above 8 and below 4 the enzyme is rapidly inactivated.
Temperature Dependence
Optimum temperature is 40-45 degrees Celsius for the hydrolase activity. Is stable at temperatures from 4 to 37 degrees Celsius. During 30 minutes of incubation at 40 degrees Celsius, about 20 to 30% of the activity is lost, and at 50 degrees Celsius only 20% of the activity is retained.
Pathway
Lipid metabolism; bile acid biosynthesis.
Features
Showing features for active site, binding site.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | peptidoglycan-based cell wall | |
Molecular Function | chenodeoxycholoyltaurine hydrolase activity | |
Molecular Function | choloylglycine hydrolase activity | |
Molecular Function | transferase activity | |
Biological Process | bile acid biosynthetic process |
Keywords
- Molecular function
- Biological process
Enzyme and pathway databases
Protein family/group databases
Chemistry
Names & Taxonomy
Protein names
- Recommended nameBile salt hydrolase/transferase
- Short namesBSH/T
- Alternative names
Gene names
Organism names
- Organism
- Strain
- Taxonomic lineageBacteria > Actinomycetota > Actinomycetes > Bifidobacteriales > Bifidobacteriaceae > Bifidobacterium
Accessions
- Primary accessionQ9KK62
Subcellular Location
UniProt Annotation
GO Annotation
Phenotypes & Variants
Features
Showing features for mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 2 | Loss of hydrolase activity. | ||||
Sequence: C → A | ||||||
Mutagenesis | 3 | About 2-fold decrease in hydrolase activity, but no change in substrate affinity. | ||||
Sequence: T → A |
PTM/Processing
Features
Showing features for initiator methionine, chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Initiator methionine | 1 | Removed | ||||
Sequence: M | ||||||
Chain | PRO_0000450324 | 2-317 | Bile salt hydrolase/transferase | |||
Sequence: CTGVRFSDDEGNTYFGRNLDWSFSYGETILVTPRGYHYDTVFGAGGKAKPNAVIGVGVVMADRPMYFDCANEHGLAIAGLNFPGYASFVHEPVEGTENVATFEFPLWVARNFDSVDEVEETLRNVTLVSQIVPGQQESLLHWFIGDGKRSIVVEQMADGMHVHHDDVDVLTNQPTFDFHMENLRNYMCVSNEMAEPTSWGKASLTAWGAGVGMHGIPGDVSSPSRFVRVAYTNAHYPQQNDEAANVSRLFHTLGSVQMVDGMAKMGDGQFERTLFTSGYSSKTNTYYMNTYDDPAIRSYAMADYDMDSSELISVAR |
Expression
Induction
Is part of an operon containing at least two genes, bsh and glnE (GlnE is glutamine synthetase adenylyltransferase).
Structure
Sequence
- Sequence statusComplete
- Length317
- Mass (Da)35,155
- Last updated2000-10-01 v1
- Checksum178B263FBBA205CC
Keywords
- Technical term