A Variant of λ Repressor with an Altered Patterned of Cooperative Binding to DNA Sites
Abstract
The bacteriophage λ repressor binds cooperatively to pairs of adjacent sites in the λ chromosome, one repressor dimer binding to each site. The repressor's amino domain (that which mediates DNA binding) is connected to its carboxyl domain (that which mediates dimerization and the interaction between dimers) by a protease-sensitive linker region. We have generated a variant λ repressor that lacks this linker region. We show that dimers of the variant protein are deficient in cooperative binding to sites at certain, but not all, distances. The linker region thus extends the range over which carboxyl domains of DNA-bound dimers can interact. In particular, the linker is required for cooperative binding to a pair of sites as found in the λ chromosome, and thus is essential for the repressor's physiological function.
- Publication:
-
Proceedings of the National Academy of Science
- Pub Date:
- August 1995
- DOI:
- 10.1073/pnas.92.18.8110
- Bibcode:
- 1995PNAS...92.8110A