EXPRESSION AND CRYSTALLIZATION OF A SOLUBLE FORM OF DROSOPHILA FASCICLIN-III

A truncated form of Drosophila fasciclin III has been engineered by si te-directed mutagenesis. Secreted fasciclin III is expressed at 35 to 40 mg/l in insect cells with baculovirus carrying the recombinant gene . Single crystals of purified soluble fasciclin III have been grown by vapor diffusion versus polyethylene glycol 8000/sodium citrate at low pH. The space group is P6(1)22 or its enantiomorph P6(5)22, with unit cell dimensions a=b=140 Angstrom, c=260 Angstrom. Cryo-preserved crys tals diffract to reciprocal lattice spacings beyond 3.0 Angstrom.