PURIFICATION, CHARACTERIZATION, CRYSTALLIZATION, AND PRELIMINARY-X-RAY RESULTS FROM PARACOCCUS-DENITRIFICANS PORIN

The porin from Paracoccus denitrificans ATCC 13543 was purified and cr ystallized. Two crystal forms were obtained from porin solutions with beta-d-octylglucopyranoside as detergent. Crystals of form I belong to the monoclinic spacegroup C2 with unit cell dimensions a = 112.2 Angs trom, b = 193.8 Angstrom, c = 100.5 Angstrom and beta = 129.2 degrees. There is 1 trimer per asymmetric unit. Crystals of form II are tricli nic with a = 89.7 Angstrom, b = 98.8 Angstrom, c = 112.5 Angstrom, alp ha = 112.5 degrees, beta = 101.8 degrees, gamma = 106.7 degrees (2 tri mers per asymmetric unit). Both crystal forms diffract to 3 Angstrom. (C) 1995 Wiley-Liss, Inc.