11-FOLD SYMMETRY OF THE TRP RNA-BINDING ATTENUATION PROTEIN (TRAP) FROM BACILLUS-SUBTILIS DETERMINED BY X-RAY-ANALYSIS

The trp RNA-binding attenuation protein (TRAP) of Bacillus subtilis ha s been crystallized and examined by crystallography using X-ray synchr otron radiation diffraction data. Crystals of TRAP complexed with L-tr yptophan belong to space group C2 with a = 156.8 Angstrom, b = 114.05 Angstrom, c = 105.9 Angstrom, beta = 118.2 degrees. Crystals of a pote ntial heavy-atom derivative of TRAP complexed with 5-bromo-L-tryptopha n grow in the same space group with similar cell dimensions. X-ray dat a for the native crystals and for the derivative have been collected t o 2.9 Angstrom and 2.2 Angstrom resolution, respectively. Peaks in the self-rotation function and in the Patterson synthesis could only be e xplained by two 11-subunit oligomers (each formed by an 11-fold axis o f symmetry) in the asymmetric unit lying with the 11-fold rotation axe s parallel to each other. The consequence is that the TRAP molecule ha s 11-fold symmetry and contains 11 subunits.