Daughter origins can be held together by O protein in phage lambda replicative intermediates.
When lambda replicative intermediates are incubated with initiator protein O, complex molecules are observed in which O interacts with both daughter origin segments and with growing points. In the simplest of these molecules it appears that daughter origins and growing points may all be bound together at a single point. When replicative intermediates are sequentially incubated with single-stranded binding protein and O protein, simpler structures are observed. In this case, both daughter origins are bound together by O protein. This result mimics that found when plasmid containing two tandem lambda origin sequences is reacted with O protein. In this case double origin binding produces a DNA loop. Double origin binding, as demonstrated in this investigation, creates the potential for topological domains which will have important effects on the ability of daughter origins to initiate replication.
Schnos
M
M
Institute for Molecular Virology, University of Wisconsin-Madison 53706.
Inman
R B
RB
D010582:Bacteriophage lambda / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
C027812:O protein, Bacteriophage lambda; D014764:Viral Proteins