AFM studies of lambda repressor oligomers securing DNA loops.

ABSTRACT: Large, cooperative assemblies of proteins that wrap and/or loop genomic DNA may "epigenetically" shift configurational equilibria that determine developmental pathways. Such is the case of the lambda bacteriophage which may exhibit virulent (lytic) or quiescent (lysogenic) growth. The lysogenic state of lambda prophages is maintained by the lambda repressor (CI), which binds to tripartite operator sites in each of the O(L) and O(R) control regions located about 2.3 kbp apart on the phage genome and represses lytic promoters. Dodd and collaborators have suggested that an initial loop formed by interaction between CI bound at O(R) and O(L) provides the proper scaffold for additional CI binding to attenuate the P(RM) promoter and avoid over production of CI. Recently, the looping equilibrium

SUBMITTER: Wang H 

PROVIDER: S-EPMC3641193 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature