Structural characterization of penicillin-binding protein-related factor A(PrfA) from Bacillus species

The prfA genes of Bacillus stearothermophilus and Bacillus subtilis are in an operon downstream of the ponA gene encoding penicillin-binding protein 1 (PBP1), a major enzyme involved in peptidoglycan synthesis. The specific f unction of the 23- to 24-kDa PrfA protein is unknown but this protein plays some role in nucleoid segregation and the functions of PrfA and PBP1 are i nterrelated. We overexpressed B. stearothermophilus and B. subtilis PrfA in Escherichia coli and purified the proteins to homogeneity by cation exchan ge and gel filtration chromatography, The protein is a monomer in solution, and circular dichroism spectroscopy revealed an abundance of beta -sheet s econdary structure. Crystals of B. stearothermophilus PrfA were also obtain ed and diffracted X-rays to 1.8 Angstrom resolution. (C) 2000 Academic Pres s.