2HEZ: Bifidobacterium Longum Bile Salt Hydrolase

Bile salt hydrolase (BSH) is an enzyme produced by the intestinal microflora that catalyzes the deconjugation of glycine- or taurine-linked bile salts. The crystal structure of BSH reported here from Bifidobacterium longum reveals that it is a member of N-terminal nucleophil hydrolase structural superfamily possessing the characteristic alphabetabetaalpha tetra-lamellar tertiary structure arrangement. Site-directed mutagenesis of the catalytic nucleophil residue, however, shows that it has no role in zymogen processing into its corresponding active form. Substrate specificity was studied using Michaelis-Menten and inhibition kinetics and fluorescence spectroscopy. These data were compared with the specificity profile of BSH from Clostridium perfrigens and pencillin V acylase from Bacillus sphaericus, for both of which the three-dimensional structures are available. Comparative analysis shows a gradation in activity toward common substrates, throwing light on a possible common route toward the evolution of pencillin V acylase and BSH.
PDB ID: 2HEZDownload
MMDB ID: 41625
PDB Deposition Date: 2006/6/22
Updated in MMDB: 2006/12
Experimental Method:
x-ray diffraction
Resolution: 2.5  Å
Source Organism:
Similar Structures:
Biological Unit for 2HEZ: tetrameric; determined by author and by software (PISA,PQS)
Molecular Components in 2HEZ
Label Count Molecule
Proteins (4 molecules)
Bile Salt Hydrolase
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB