TABLE 1.
rpoS sequences in chemostat isolates
| Change in nucleotide sequencea | Change in amino acid sequence | Glycogen productionc | Catalase activityd | No. of isolates sequencede |
|---|---|---|---|---|
| Controls | ||||
| Wild type RpoS | ++++ | ++++ | ||
| rpoS::Tn10 | − | − | ||
| Isolatesb | ||||
| G to T at 297* | Leucine to phenylalanine at aaf 99 | ++ | ++ | 3 |
| T to A at 383* | Isoleucine to asparagine at aa 128 | ++ | ++ | 1 |
| T to G at 515 | Valine to glycine at aa 172 | − | − | 1 |
| G to T at 814* | Glutamic acid to stop codon at aa 272 | − | − | 1 |
| Δ484–487* | Truncation; retains first 161 native aa + 10 nonsense aa added | − | − | 1 |
| Δ151–155* | Truncation; retains first 50 native aa + 12 nonsense aa added | − | − | 1 |
| Δ393–397 | Truncation; retains first 131 native aa + 2 nonsense aa added | − | − | 6 |
| ΔA at 900 | Truncation; retains first 299 native aa + 23 nonsense aa added | − | − | 1 |
| A insertion at 571 | Truncation; retains first 190 native aa + 2 nonsense aa added | − | − | 2 |
| Δ249–345 | In-frame deletion of 32 aa (Δ44–75) | − | − | 1 |
a
Numbering of sequences is from the first nucleotide in the start codon
b
rpoS sequences are from unstained colonies screened with iodine for glycogen after 4 days of culture. The isolates were from two independent glucose-limited chemostats growing at a D = value of 0.3 h−1. The mutations from the first population are marked with asterisks.
c
Glycogen production was tested as described for Fig. 1.
d
Catalase activity was tested by visual comparison of the bubbling activity of colonies in the presence of H2O2.
e
Number of isolates with the same sequence analyzed.
f
aa, amino acid.