The Fkh1 Forkhead associated domain promotes ORC binding to a subset of DNA replication origins in budding yeast.
Nucleic Acids Res
; 49(18): 10207-10220, 2021 10 11.
Article
in En
| MEDLINE
| ID: mdl-34095951
ABSTRACT
The pioneer event in eukaryotic DNA replication is binding of chromosomal DNA by the origin recognitioncomplex (ORC). The ORC-DNA complex directs the formation of origins, the specific chromosomal regions where DNA synthesis initiates. In all eukaryotes, incompletely understood features of chromatin promote ORC-DNA binding. Here, we uncover a role for the Fkh1 (Forkhead homolog) protein and its forkhead associated (FHA) domain in promoting ORC-origin binding and origin activity at a subset of origins in Saccharomyces cerevisiae. Several of the FHA-dependent origins examined required a distinct Fkh1 binding site located 5' of and proximal to their ORC sites (5'-FKH-T site). Genetic and molecular experiments provided evidence that the Fkh1-FHA domain promoted origin activity directly through Fkh1 binding to this 5' FKH-T site. Nucleotide substitutions within two relevant origins that enhanced their ORC-DNA affinity bypassed the requirement for their 5' FKH-T sites and for the Fkh1-FHA domain. Significantly, assessment of ORC-origin binding by ChIPSeq provided evidence that this mechanism was relevant at â¼25% of yeast origins. Thus, the FHA domain of the conserved cell-cycle transcription factor Fkh1 enhanced origin selection in yeast at the level of ORC-origin binding.
Full text:
1
Database:
MEDLINE
Main subject:
Saccharomyces cerevisiae
/
DNA, Fungal
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Cell Cycle Proteins
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Saccharomyces cerevisiae Proteins
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Origin Recognition Complex
/
Forkhead Transcription Factors
Type of study:
Risk_factors_studies
Language:
En
Year:
2021
Type:
Article