Enforcement of late replication origin firing by clusters of short G-rich DNA sequences.
Previous studies in budding yeast suggested that the default firing time of most DNA replication origins is early in S phase and that origins can be forced to fire later by proximity to certain cis-acting sequences. However, these cis-acting sequences were not well defined. We have attempted to characterize cis-acting sequences that affect replication timing in the fission yeast. We identified a stretch of 200 bp that was sufficient to compel nearby origins to fire late. The 200-bp stretch was able to force an origin to fire late whether adjacent to the origin or approximately 800 bp away in opposite orientation. The stretch contains a cluster of three close matches to a G-rich, 10-bp late consensus sequence (LCS). The three LCS elements cooperate with each other and with other sequences within the 200-bp stretch to enforce late replication. Although only a few origins that fire in very late S phase have been identified in fission yeast, all of them are located close to a cluster of LCS elements.
Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York 14263-0001, USA.
Chulee
C
Yompakdee
Joel A
JA
Huberman
D001483:Base Sequence; D016384:Consensus Sequence; D042522:DNA Replication Timing / Q000235:genetics*; D006147:Guanine; D018741:Replication Origin / Q000502:physiology*; D016196:S Phase; D012568:Schizosaccharomyces / Q000235:genetics*
D006147:Guanine