TABLE 2.
Pneumococcal transformation studies
| Recipient | Transforming DNAa | Penicillin MIC for transformants (μg/ml) | Integration of altered PBPs in transformants |
|---|---|---|---|
| Strain R6 | PBP 2B | 0.03 | No |
| Strain R6 | PBP 1A | 0.03 | No |
| Strain R6 | PBPs 2B and 1A | 0.03 | No |
| Strain R6 | PBP 2X | 0.06 | Yes; PBP 2X |
| Strain R6 | PBPs 2X and 1A | 0.06 | Yes; PBP 2X |
| Strain R6 | PBPs 2X and 2B | 0.25 | Yes; PBPs 2X and 2B |
| Strain R6 | PBPs 2X, 2B, and 1A | 0.25 | Yes; PBPs 2X and 2B |
| 2X/2B-R6 mutant | PBP 1A | 1.5 | Yes; PBPs 2X, 2B, and 1A |
| 2X/2B-R6 mutant | Mutagenized PBP 1A(371) | 0.5 | Yes; PBPs 2X, 2B, and 1A(371) |
| 2X/2B-R6 mutant | Mutagenized PBP 1A(574–577) | 0.375 | Yes; PBPs 2X, 2B, and 1A(574–577) |
a
Cloned PBP 2X, 2B, and 1A “resistance” genes from penicillin-resistant isolate 8303 were used as transforming DNA. The superscript numbers indicate the amino acid positions at which mutagenesis occurred.