CRYSTALLIZATION OF A GENETICALLY-ENGINEERED WATER-SOLUBLE PRIMARY PENICILLIN TARGET ENZYME - THE HIGH-MOLECULAR-MASS PBP2X OF STREPTOCOCCUS-PNEUMONIAE

A genetically engineered water-soluble derivative of PBP2x of Streptococcus pneumoniae has been produced, purified and crystallized in a form suitable for X-ray diffraction analysis. The best crystals have been grown at 15°C, from solutions containing 8% polyethylene glycol 10,000 at pH values ranging from 3.9 to 6.0. These crystals diffract to a resolution of 3.5 Å and have a space group P6122 (or enantiomorph) with unit cell dimensions of a = b = 162.2 Å, c = 171.8 Å, α = β = 90°, β = 120°. The molecular mass and cell dimensions suggest that there is one molecule of enzyme per asymmetric unit. The breakdown of a chromogenic cephalosporin derivative diffused into a crystal reveals clearly that the enzyme is active in the crystalline state. © 1993 Academic Press Limited.