TABLE 2.
Codon usage in recombinant genes and effect of amplification of tRNA-encoding genes on expression in E. coli
| Plasmid | Codon usage (%)
|
Effect of tRNA gene amplification on expressiona
|
||||
|---|---|---|---|---|---|---|
| ATA | AGA | CTA | ileX (ATA) | argU (AGA) | leuW (CTA) | |
| PETBoNT/A-L22Km | 3.8 (19)b | 2.0 (10) | 1.0 (5) | ++ | − | − |
| PETBoNT/B-L10 | 6.2 (29) | 2.3 (11) | 0.2 (1) | ++ | + | − |
| pETBoNT/C-L20 | 5.9 (28) | 3.1 (15) | 0.8 (4) | ++ | − | − |
| pETBoNT/E-L31 | 4.0 (18) | 2.4 (11) | 1.5 (7) | ++ | + | − |
| pETBoNT/B-H18 | 6.4 (57) | 1.9 (17) | 1.0 (9) | ++ | + | − |
| pETBoNT/C-H14 | 5.0 (48) | 2.5 (24) | 0.9 (9) | ++ | + | − |
| pETBoNT/E-H10 | 4.4 (40) | 2.2 (20) | 0.3 (3) | ++ | + | − |
| pTSC3-7 | 2.4 (6) | 3.2 (8) | 0.8 (2) | +/− | +/− | − |
| pETiota11Km | 5.1 (23) | 1.7 (8) | 0.8 (4) | + | − | − |
| pETTeNT-L12Km | 4.8 (24) | 1.8 (9) | 1.4 (7) | + | − | − |
| pETTeNT-H4Km | 5.7 (53) | 1.8 (17) | 1.1 (11) | ++ | + | − |
| pETPA5 | 0 | 0 | 0 | − | − | − |
| pETI10PA10 | 2.5 (10) | 0 | 0 | ++ | − | − |
| pETR10PA25 | 0 | 2.5 (10) | 0 | − | ++ | − |
| pETL10PA32 | 0 | 0 | 2.5 (10) | − | − | ++ |
a
++, strong effect; +, moderate effect; −, no effect; +/−, weak effect.
b
The values in parentheses are numbers of codons in the coding sequence.