4B6J: Crystal Structure Of Phosphoserine Phosphatase From T. Onnurineus

Phosphoserine phosphatase (PSP) catalyzes the final and irreversible step of L-serine synthesis by hydrolyzing phosphoserine to produce L-serine and inorganic phosphate. Developing a therapeutic drug that interferes with serine production is of great interest to regulate the pathogenicity of some bacteria and control D-serine levels in neurological diseases. We determined the crystal structure of PSP from the hyperthermophilic archaeon Thermococcus onnurineus at 1.8 A resolution, revealing an NDSB ligand bound to a novel site that is located in a fissure between the catalytic domain and the CAP module. The structure shows a half-open conformation of the CAP 1 module with a unique protruding loop of residues 150-155 that possesses a helical conformation in other structures of homologous PSPs. Activity assays indicate that the enzyme exhibits marginal PSP activity at low temperature but a sharp increase in the kcat /KM value, approximately 22 fold, when the temperature is increased. Structural and biochemical analyses suggest that the protruding loop in the active site might be an essential component for the regulation of the activity of PSP from hyperthermophilic T. onnurineus. Identification of this novel binding site distantly located from the catalytic site may be exploited for the development of effective therapeutic allosteric inhibitors against PSP activity. (c) Proteins 2013. (c) 2012 Wiley Periodicals, Inc.
PDB ID: 4B6JDownload
MMDB ID: 106177
PDB Deposition Date: 2012/8/14
Updated in MMDB: 2012/12
Experimental Method:
x-ray diffraction
Resolution: 3.34  Å
Source Organism:
Similar Structures:
Biological Unit for 4B6J: octameric; determined by software (PISA)
Molecular Components in 4B6J
Label Count Molecule
Proteins (8 molecules)
Phosphoserine Phosphatase
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB