Discrete functional elements required for initiation activity of the Chinese hamster dihydrofolate reductase origin beta at ectopic chromosomal sites.

ABSTRACT: The Chinese hamster dihydrofolate reductase (DHFR) DNA replication initiation region, the 5.8 kb ori-beta, can function as a DNA replicator at random ectopic chromosomal sites in hamster cells. We report a detailed genetic analysis of the DiNucleotide Repeat (DNR) element, one of several sequence elements necessary for ectopic ori-beta activity. Deletions within ori-beta identified a 132 bp core region within the DNR element, consisting mainly of dinucleotide repeats, and a downstream region that are required for ori-beta initiation activity at non-specific ectopic sites in hamster cells. Replacement of the DNR element with Xenopus or mouse transcriptional elements from rDNA genes restored full levels of initiation activity, but replacement with a nucleosome positioning element or a viral

SUBMITTER: Gray SJ 

PROVIDER: S-EPMC1810229 | biostudies-literature | 2007 Jan

REPOSITORIES: biostudies-literature