Ribosomal and DNA binding proteins (DNA bp II) from an extreme thermophilic bacterium, B.caldolyticus strain EP 00275, were investigated for stability and crystallization and compared to the homologous proteins from B.stearothermophilus. Two-dimensional gel electrophoresis of both types of proteins, the amino acid composition and the sequences of some of the peptides of DNA bp II revealed a close relationship between each other. The physico-chemical characteristics of DNA bp II were similar but different from homologous proteins from T. thermophilus and C. pasteurineum. From our results we conclude: B. stearothermophilus and B. caldolyticus strain EP 00275 are similar organisms with regard to their ribosomal and DNA binding proteins.
