Crystal Structure of the lamda Repressor and a Model for Pairwise Cooperative Operator Binding

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Nature

DOI:https://doi.org/10.1038/nature06831· OSTI ID:959512

Stayrook, S; Jaru-Ampornpan, P; Ni, J; Hochschild, A; Lewis, M

Bacteriophage {lambda} has for many years been a model system for understanding mechanisms of gene regulation1. A 'genetic switch' enables the phage to transition from lysogenic growth to lytic development when triggered by specific environmental conditions. The key component of the switch is the cI repressor, which binds to two sets of three operator sites on the chromosome that are separated by about 2,400 base pairs (bp)2, 3. A hallmark of the system is the pairwise cooperativity of repressor binding4. In the absence of detailed structural information, it has been difficult to understand fully how repressor molecules establish the cooperativity complex. Here we present the X-ray crystal structure of the intact cI repressor dimer bound to a DNA operator site. The structure of the repressor, determined by multiple isomorphous replacement methods, reveals an unusual overall architecture that allows it to adopt a conformation that appears to facilitate pairwise cooperative binding to adjacent operator sites.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: Doe - Office Of Science
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 959512
• Report Number(s): BNL--82498-2009-JA
• Journal Information: Nature, Journal Name: Nature Vol. 452
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ARCHITECTURE
BACTERIOPHAGES
CHROMOSOMES
CRYSTAL STRUCTURE
DIMERS
DNA
GENES
national synchrotron light source