A variant of lambda repressor with an altered pattern of cooperative binding to DNA sites.

AUTOR(ES)

Astromoff, A

RESUMO

The bacteriophage lambda repressor binds cooperatively to pairs of adjacent sites in the lambda 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 lambda 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 lambda chromosome, and thus is essential for the repressor's physiological function.

Documentos Relacionados

• Cooperative binding of an Ultrabithorax homeodomain protein to nearby and distant DNA sites.
• Proposed mechanism of bacteriophage lambda induction: acquisition of binding sites for lambda repressor by DNA of the host.
• Computer simulations and experimental studies of gel mobility patterns for weak and strong non-cooperative protein binding to two targets on the same DNA: application to binding of tet repressor variants to multiple and single tet operator sites.
• Interactions of the transposase with the ends of Mu: formation of specific nucleoprotein structures and non-cooperative binding of the transposase to its binding sites.
• EFFECT OF THE LAMBDA REPRESSOR ON THE BINDING OF RNA POLYMERASE TO DNA