Table 1.

Complementation of the Escherichia coli RNase P mutant strain by Bacillus subtilis rnpB

	DW2/pDW160		DW2 doubling time (min)*
RNase P RNA source	30°C	43°C	37°C
pSP64-EcrnpB	+++	+++‡	75±7
pSP64-BsrnpB	+++	+++§	64±4
pSP64	+++	—
Growth of mutant strains transformed with E. coli or B. subtilis rnpB was analysed on LB plates at the permissive (30°C) and non-permissive (43°C) temperature. RNase P, ribonuclease P; +++, good complementation; —, no colonies.
*Measured after elimination of pDW160.
‡Colonies at 43°C were smaller than those at 30°C; for growth at 43°C, the phenotype of cells transformed with E. coli rnpB was set as the standard.
§Colonies at 43°C were larger than those for cells transformed with E. coli rnpB, set as the standard.