2BHS: Crystal Structure Of Cysteine Synthase B

The enzyme O-acetylserine sulfhydrylase participates in the biosynthesis of l-cysteine in bacteria and plants. The structure of isoenzyme B (CysM) from Escherichia coli was established in a hexagonal crystal form at 2.7 A resolution (wild-type) and in a merohedrally twinned tetragonal crystal form at 2.1 A resolution (surface mutant). Structural superpositions revealed the variations with respect to isoenzyme A (CysK) and explained the different substrate specificities. A geometric model of the reaction catalyzed by CysM is proposed. Both isoenzymes are used for the production of l-amino acid derivatives as building blocks for the synthesis of peptides and peptidomimetic drugs. Since the structure of CysM revealed a remarkable main chain variation at the active center, it constitutes a further starting point for engineering mutants with novel substrate specificities.
PDB ID: 2BHSDownload
MMDB ID: 33987
PDB Deposition Date: 2005/1/18
Updated in MMDB: 2011/10
Experimental Method:
x-ray diffraction
Resolution: 2.67  Å
Source Organism:
Similar Structures:
Biological Unit for 2BHS: dimeric; determined by author and by software (PQS)
Molecular Components in 2BHS
Label Count Molecule
Proteins (2 molecules)
Cysteine Synthase B(Gene symbol: cysM)
Molecule annotation
Chemicals (2 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB