W0135

Improved Crystallization and Diffraction of Pfu-35386: From Twinned to un-Twinned Crystals. Jeff Habel, Ashit Shah, Zhi-Jie Liu, John Rose, Bi-Cheng Wang, Dept. of BIochemistry, Univ. of Georgia, B204 Life Science Bldg., Athens, GA 30602 USA.

Initial crystallization results of the Pyrococcus furiosis open reading frame #35386, demonstrated a thin plate morphology crystal. To make matters worse, twinning of these crystals was prolific perpendicular to the crystal face in addition to parallel along the crystal face (possible screw dislocation). “Single” crystals cut from clusters were mounted and did diffract to ~2.6Å resolution. However, data was not collected due to severe twinning in the diffraction spots.

Improvement of this crystallization condition was initiated using batch crystallization. A decrease in protein concentration yielded reduced twinning and a thickening of the crystal, but single crystals could not be obtained by reduced protein concentration alone. Streak seeding ultimately produced un-twinned crystals. These crystals diffract to ~2.3Å resolution and are in space group P2₁ with cell constants a = 47.06, b = 67.60, c = 49.41 and ß = 92.09. Structure determination is in progress.

Work supported in part with funds from the National Institute of Health (GM62407), The Georgia Research Alliance, and The University of Georgia Research Foundation.