Crystallization and preliminary X-ray crystallographic studies of the native and chemically modified anion-selective porin from Comamonas acidovorans.
Omp32, the strongly anion-selective porin from Comamonas acidovorans, has been crystallized. Two crystal forms were observed, both of which belong to space group R3, but exhibit different cell dimensions a = b = 106.7, c = 140.6 A (crystal form I) and a = b = 87.1, c = 135.3 A (crystal form II) with one trimer per asymmetric unit. The crystals diffract to 2.2 and 2.3 A resolution, respectively. Omp32 was chemically modified by introducing negative charges through succinylation. The number and positions of the individual modifications were determined using mass spectrometry and X-ray crystallography. Chemically modified porins yielded crystals of a third form, also of space group R3 but with cell constants of a = b = 109.3 and c = 263.2 A (crystal form III), showing a virtually doubled c axis. Crystals of form III diffract to 3.5 A resolution.
Zeth
K
K
Max-Planck-Institut für Biochemie, Am Klopferspitz 18a, D-82152 Martinsried, Germany.
Schnaible
V
V
Przybylski
M
M
Welte
W
W
Diederichs
K
K
Engelhardt
H
H
D001426:Bacterial Proteins / Q000737:chemistry* / Q000302:isolation & purification; D003460:Crystallization; D018360:Crystallography, X-Ray; D006090:Gram-Negative Bacteria / Q000737:chemistry*; D018272:Porins / Q000737:chemistry* / Q000302:isolation & purification; D011487:Protein Conformation; D012542:Scattering, Radiation; D017550:Spectroscopy, Fourier Transform Infrared
D001426:Bacterial Proteins; C115885:Omp32 protein, bacteria; D018272:Porins