TABLE 1.
Strains and plasmids used in this study
| Strain or plasmid | Genotype, phenotype, or description | Reference or source |
|---|---|---|
| Strains | ||
| A. brasilense Sp7 | Wild-type strain | ATCC 29145 |
| E. coli | ||
| DH5α | General cloning strain | Gibco BRL |
| RP437 | Wild-type chemotaxis strain | J. S. Parkinson |
| RP1616 | ΔcheZ; tumbly | J. S. Parkinson |
| RP4606 | ΔcheW; smooth swimming | J. S. Parkinson |
| RP5232 | ΔcheY; smooth swimming | J. S. Parkinson |
| RP2768 | cheY201; smooth swimming | J. S. Parkinson |
| Plasmids | ||
| pFAJ451 | pLAFR1 derivative containing 25 kb of A. brasilense DNA, including the chemotaxis operon | 16 |
| pTrc99A | Expression vector; Ptac-based promoter; Apr | Amersham |
| pProExHTa | Expression vector; Ptac-based promoter; 6-His N-terminal tag to the expressed protein; Apr | Gibco BRL |
| pIZ101 | cheW gene from A. brasilense cloned as an NcoI/HindIII DNA fragment in pTrc99A | This work |
| pIZ103 | cheY gene from A. brasilense cloned as a BamHI/XhoI DNA fragment in pProEXHTa | This work |
| pIZ103D52N | Derivative of pIZ103, carrying a mutant cheY gene which encodes the mutated protein CheYD52N | This work |
| pIZ109 | cheY from A. brasilense cloned as an EcoRI/HindIII DNA fragment in pTrc99A | This work |