4ITU: Crystal Structure Of S-2-hydroxypropyl Coenzyme M Dehydrogenase (s- Hpcdh) Bound To S-hpc And Nadh

(R)- and (S)-hydroxypropyl-coenzyme M dehydrogenases (R- and S-HPCDH) are stereospecific enzymes that are central to the metabolism of propylene and epoxide in Xanthobacter autotrophicus. The bacterium produces R- and S-HPCDH simultaneously to facilitate transformation of R- and S-enantiomers of epoxypropane to a common achiral product 2-ketopropyl-CoM (2-KPC). Both R- and S-HPCDH are highly specific for their respective substrates as each enzyme displays less than 0.5% activity with the opposite substrate isomer. In order to elucidate the structural basis for stereospecificity displayed by R- and S-HPCDH we have determined substrate bound crystal structures of S-HPCDH to 1.6A resolution. Comparisons to the previously reported product-bound structure of R-HPCDH reveal that although the placement of catalytic residues within the active site of each enzyme is nearly identical, structural differences in the surrounding area provide each enzyme with a distinct substrate binding pocket. These structures demonstrate how chiral discrimination by R- and S-HPCDH results from alternative binding of the distal end of substrates within each substrate binding pocket.
PDB ID: 4ITUDownload
MMDB ID: 108699
PDB Deposition Date: 2013/1/18
Updated in MMDB: 2013/04
Experimental Method:
x-ray diffraction
Resolution: 1.6  Å
Source Organism:
Similar Structures:
Biological Unit for 4ITU: tetrameric; determined by author and by software (PISA)
Molecular Components in 4ITU
Label Count Molecule
Proteins (4 molecules)
Short-chain Dehydrogenase/reductase SDR
Molecule annotation
Chemicals (8 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB