Previous Article | Next Article ![]()
Molecular and Cellular Biology, December 2001, p. 8095-8103, Vol. 21, No. 23
National Institute of Child Health and Human
Development, National Institutes of Health, Bethesda, Maryland
20892-2753
Received 9 July 2001/Returned for modification 22 August
2001/Accepted 31 August 2001
The mechanism by which origin recognition complexes
(ORCs) identify replication origins was investigated using purified Orc proteins from Schizosaccharomyces pombe. Orc4p alone
bound tightly and specifically to several sites within
S. pombe replication origins that are
genetically required for origin activity. These sites consisted of
clusters of A or T residues on one strand but were devoid of either
alternating A and T residues or GC-rich sequences. Addition of a
complex consisting of Orc1, -2, -3, -5, and -6 proteins (ORC-5) altered
neither Orc4p binding to origin DNA nor Orc4p protection of specific
sequences. ORC-5 alone bound weakly and nonspecifically to DNA; strong
binding required the presence of Orc4p. Under these conditions, all six
subunits remained bound to chromatin isolated from each phase of the
cell division cycle. These results reveal that the S.
pombe ORC binds to multiple, specific sites within
replication origins and that site selection, at least in vitro, is
determined solely by the Orc4p subunit.
0270-7306/01/$04.00+0 DOI: 10.1128/MCB.21.23.8095-8103.2001
Site-Specific DNA Binding of the Schizosaccharomyces
pombe Origin Recognition Complex Is Determined by the
Orc4 Subunit
*
Corresponding author. Mailing address: National
Institute of Child Health and Human Development, Building 6, Room 416, National Institutes of Health, 9000 Rockville Pike, Bethesda, MD
20892-2753. Phone: (301) 402-8234. Fax: (301) 480-9354. E-mail:
depamphm{at}mail.nih.gov.
This article has been cited by other articles:
| J. Bacteriol. | J. Virol. | Eukaryot. Cell |
|---|
| Microbiol. Mol. Biol. Rev. | Clin. Vaccine Immunol. | All ASM Journals |
|---|