Table 2. Site-saturation mutagenesis of codon-666 of PilQ.
The amino acids at position-666 of PilQ that increased penicillin resistance and disrupted formation of the SDS-resistant multimer.
| Amino Acid at Position-666 | No. Clones Isolated | MICpen (μg/ml) |
|---|---|---|
| Glutamate | pilQ Wild Type | 0.5 |
| Lysine | pilQ2 | 1.2 |
| Alanine | 2 | 1.2 |
| Cysteine | 6 | 1.2 |
| Glycine | 7 | 1.2 |
| Isoleucine | 4 | 1.2 |
| Leucine | 3 | 1.2 |
| Phenylalanine | 1 | 1.2 |
| Serine | 1 | 1.2 |
| Threonine | 3 | 1.2 |
| Tryptophan | 1 | 1.2 |
| Tyrosine | 1 | 1.2 |
| Valine | 4 | 1.2 |
| Argininea | Site-directed | 1.2 |
| Aspartic Acida | Site-directed | (0.5)b |
| Glutaminea | Site-directed | (0.5)b |
a
Constructed by site-directed mutagenesis.
b
Not determined; transformation of SZ3 with pUC18-pilQ E666D or pUC18-pilQ E666Q did not give rise to resistant colonies above negative controls.