TABLE 3.
Summary of Ile-dependent growth assays with peptide transport mutantsa
| Strain | Growth (OD600) with peptidea
|
||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| AI | KI | RI | VI | FI | IS | AK | Trib | Tetrab | Hexab | Nonab | |
| WT | 0.37 ± 0.04 | 0.37 ± 0.04 | 0.40 ± 0.04 | 0.42 ± 0.05 | 0.41 ± 0.04 | 0.38 ± 0.04 | 0.05 ± 0.02 | 0.41 ± 0.03 | 0.36 ± 0.02 | 0.36 ± 0.02 | 0.14 ± 0.01 |
| oppA | 0.39 ± 0.05c | 0.40 ± 0.04c | 0.38 ± 0.02c | 0.42 ± 0.01c | 0.37 ± 0.03c | 0.42 ± 0.06c | 0.05 ± 0.01c | 0.38 ± 0.03c | 0.36 ± 0.03c | 0.36 ± 0.06c | 0.14 ± 0.00c |
| oppB | 0.22 ± 0.04 | 0.26 ± 0.04 | 0.18 ± 0.04 | 0.18 ± 0.04 | 0.30 ± 0.01 | 0.27 ± 0.03 | 0.05 ± 0.01c | 0.26 ± 0.01 | 0.29 ± 0.01 | 0.38 ± 0.03c | 0.22 ± 0.01 |
| oppC | 0.42 ± 0.02c | 0.36 ± 0.04c | 0.37 ± 0.04c | 0.44 ± 0.03c | 0.40 ± 0.04c | 0.38 ± 0.04c | 0.06 ± 0.00c | 0.43 ± 0.04c | 0.42 ± 0.03 | 0.38 ± 0.05c | 0.19 ± 0.01 |
| oppB oppC | 0.27 ± 0.03 | 0.29 ± 0.01 | 0.29 ± 0.03 | 0.26 ± 0.02 | 0.26 ± 0.01 | 0.25 ± 0.03 | 0.07 ± 0.00c | 0.24 ± 0.02 | 0.30 ± 0.01 | 0.35 ± 0.01c | 0.22 ± 0.04 |
| dppA | 0.07 ± 0.02 | 0.25 ± 0.01 | 0.31 ± 0.01 | 0.14 ± 0.01 | 0.38 ± 0.03c | 0.06 ± 0.01 | 0.04 ± 0.01c | 0.25 ± 0.02 | 0.28 ± 0.01 | 0.06 ± 0.01 | 0.04 ± 0.01 |
| dppB | 0.10 ± 0.01 | 0.28 ± 0.02 | 0.27 ± 0.02 | 0.19 ± 0.01 | 0.35 ± 0.04 | 0.06 ± 0.01 | 0.04 ± 0.01c | 0.33 ± 0.03 | 0.37 ± 0.03c | 0.05 ± 0.01 | 0.04 ± 0.00 |
| dppC | 0.07 ± 0.01 | 0.22 ± 0.01 | 0.32 ± 0.02 | 0.14 ± 0.01 | 0.25 ± 0.02 | 0.05 ± 0.01 | 0.06 ± 0.01c | 0.14 ± 0.04 | 0.34 ± 0.01 | 0.05 ± 0.00 | 0.05 ± 0.00 |
| dppB dppC | 0.06 ± 0.00 | 0.21 ± 0.03 | 0.32 ± 0.04 | 0.19 ± 0.02 | 0.22 ± 0.02 | 0.07 ± 0.01 | 0.06 ± 0.00c | 0.10 ± 0.01 | 0.32 ± 0.03 | 0.06 ± 0.01 | 0.05 ± 0.00 |
| dppA oppA | 0.07 ± 0.01 | 0.27 ± 0.01 | 0.33 ± 0.02 | 0.14 ± 0.01 | 0.35 ± 0.01 | 0.07 ± 0.01 | 0.04 ± 0.01c | 0.23 ± 0.02 | 0.24 ± 0.01 | 0.05 ± 0.00 | 0.05 ± 0.00 |
| dppB oppB | 0.06 ± 0.00 | 0.23 ± 0.02 | 0.16 ± 0.04 | 0.18 ± 0.01 | 0.13 ± 0.01 | 0.06 ± 0.00 | 0.07 ± 0.00c | 0.25 ± 0.02 | 0.23 ± 0.01 | 0.06 ± 0.00 | 0.05 ± 0.00 |
Results shown are the average OD600 values for three independent assays with cells grown for 24 h in CDM supplemented with the indicated peptide as the sole Ile source. The initial culture OD600 was ∼0.05. Growth of the mutants was statistically significantly less than that of the parent strain (P < 0.05) unless indicated otherwise. Conditions under which no growth occurred are indicated in bold.
All amino acid sequences can be found in Table 2.
Growth data statistically indistinguishable from that for the wild type (P > 0.05).