Crystallization and preliminary X-ray crystallographic analysis of PdxJ, the pyridoxine 5'-phosphate synthesizing enzyme.
The enzyme PdxJ catalyzes the condensation of 1-deoxy-D-xylulose-5-phosphate (DXP) and 1-amino-3-oxo-4-(phosphohydroxy)propan-2-one to form pyridoxine 5'-phosphate (PNP). The protein from Escherichia coli has been crystallized in several forms under different conditions. The best diffracting crystals were obtained by a combination of the hanging-drop vapour-diffusion and microseeding techniques. Using an in-house image plate, the PdxJ crystals diffracted under cryo-conditions to 2.6 A resolution. The space group has been determined as C222(1), with unit-cell parameters a = 132.5, b = 154. 4, c = 131.4 A, corresponding to four monomers per asymmetric unit. In the search for heavy-atom derivatives, a mercury derivative has been interpreted. The 12 mercury sites located are related by 222 symmetry and, in combination with self-rotation search analyses and gel-filtration experiments, indicate the quaternary assembly of PdxJ into octamers with 422 symmetry.
Garrido Franco
M
M
Max-Planck-Institute of Biochemistry, Department of Structural Investigation, Am Klopferspitz 18a, D-82152 Martinsried, Germany.
Huber
R
R
Schmidt
F S
FS
Laber
B
B
Clausen
T
T
D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003460:Crystallization; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics; D029968:Escherichia coli Proteins; D008025:Ligases; D020836:Protein Structure, Quaternary; D011732:Pyridoxal Phosphate / Q000031:analogs & derivatives / Q000096:biosynthesis
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C098854:PdxJ protein, E coli; D011732:Pyridoxal Phosphate; D008025:Ligases; C024593:pyridoxine 5-phosphate