Roppongi_2017_Acta.Crystallogr.F.Struct.Biol.Commun_73_601

Dipeptidyl aminopeptidase IV (DAP IV or DPP IV) from Pseudoxanthomonas mexicana WO24 (PmDAP IV) preferentially cleaves substrate peptides with Pro or Ala at the P1 position [NH2-P2-P1(Pro/Ala)-P1'-P2'...]. For crystallographic studies, the periplasmic form of PmDAP IV was overproduced in Escherichia coli, purified and crystallized in complex with the tripeptide Lys-Pro-Tyr using the hanging-drop vapour-diffusion method. Kinetic parameters of the purified enzyme against a synthetic substrate were also determined. X-ray diffraction data to 1.90 A resolution were collected from a triclinic crystal form belonging to space group P1, with unit-cell parameters a = 88.66, b = 104.49, c = 112.84 A, alpha = 67.42, beta = 68.83, gamma = 65.46 degrees . Initial phases were determined by the molecular-replacement method using Stenotrophomonas maltophilia DPP IV (PDB entry 2ecf) as a template and refinement of the structure is in progress.