The N-terminal arms of lambda repressor wrap around the operator DNA

Area of Science:

• Molecular biology
• Genetics
• Biochemistry

Background:

• The lambda repressor protein controls the lysogenic cycle in bacteriophage lambda.
• Understanding repressor-operator interactions is crucial for gene regulation studies.

Purpose of the Study:

• To investigate the structural basis of lambda repressor binding to its operator DNA sequence.
• To determine the role of the N-terminal residues in DNA binding.

Main Methods:

• Chemical modification of operator DNA bases.
• Analysis of repressor fragment protection against modification.

Main Results:

• Different fragments of the lambda repressor exhibited varying abilities to protect operator DNA.
• The N-terminal residues of the repressor were implicated in DNA binding.

Conclusions:

• The N-terminal residues of the lambda repressor likely form an extended arm.
• This arm interacts with the back of the DNA helix during repressor-operator binding.