Figure 2.

Crystals and diffraction image from PPM crystallized without Mn²⁺. (a) Crystals of PPM without additional manganese. Crystals of PPM that grew without manganese in reservoir solution containing 33–36% PEG 6000, 100 mM MES pH 6.5, 100–300 mM ammonium sulfate at 291 K had a needle morphology. The black bar represents 100 µm. (b) Diffraction from crystals of PPM without additional manganese. Diffraction from these crystals identified that they belonged to space group P2₁2₁2₁. The crystals diffracted to ∼2 Å but the spots were oblate and split in the outer resolution shells (inset). A data set consisting of 120 frames using 1° oscillations per frame that is 97.1% complete to 2.5 Å was collected on beamline ID-21-G at APS.