Differential DNA affinity specifies roles for the origin recognition complex in budding yeast heterochromatin.
The origin recognition complex (ORC) marks chromosomal positions as replication origins and is essential for replication initiation. At a few loci, the ORC functions in heterochromatin formation. We show that the ORC's two roles at the heterochromatic HMRa locus in Saccharomyces cerevisiae were regulated by differences in the ORC's interaction with its target site. At HMRa, a strong ORC-DNA interaction inhibited and delayed replication initiation but promoted heterochromatin formation, whereas a weak ORC-DNA interaction allowed for increased and earlier replication initiation but reduced heterochromatin formation. Therefore, the ORC's interaction with its target site could modulate ORC activity within a heterochromatin domain in vivo.
Palacios DeBeer
Madeleine A
MA
Department of Biomolecular Chemistry, University of Wisconsin Medical School, Madison, Wisconsin 53706, USA.
Muller
Ulrika
U
Fox
Catherine A
CA
D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins; D020868:Gene Silencing; D006570:Heterochromatin / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D051738:Origin Recognition Complex; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D013997:Time Factors
D004268:DNA-Binding Proteins; D006570:Heterochromatin; D051738:Origin Recognition Complex; D004247:DNA