- Identification of the rph (RNase PH) gene of Bacillus subtilis: evidence for suppression of cold-sensitive mutations in Escherichia coli. Craven, M.G., Henner, D.J., Alessi, D., Schauer, A.T., Ost, K.A., Deutscher, M.P., Friedman, D.I. J. Bacteriol. (1992)