Abstract
The origin recognition complex (ORC) binds to origins of replication in budding yeast. We have cloned a Xenopus homolog of the largest ORC polypeptide (XORC1). Immunodepletion of XOrc1 from Xenopus egg extracts blocks the initiation of DNA replication. We have purified Xenopus ORC, consisting of a protein complex similar to yeast ORC. In Xenopus egg extracts, ORC associates with chromatin throughout G1 and S phases. RLF-M, a component of the replication licensing system, also associates with chromatin early in the cell cycle but dissociates during S phase. We show that the assembly of RLF-M onto chromatin is dependent on the presence of chromatin-bound ORC, leading to sequential assembly of initiation proteins onto replication origins during the cell cycle.
| Original language | English |
|---|---|
| Pages (from-to) | 287-96 |
| Number of pages | 10 |
| Journal | Cell |
| Volume | 87 |
| Issue number | 2 |
| Publication status | Published - 1996 |
Keywords
- Amino Acid Sequence
- Animals
- Base Sequence
- Cell Cycle
- Cell-Free System
- Chromatin
- Cloning, Molecular
- DNA Replication
- DNA-Binding Proteins
- Humans
- Immunologic Techniques
- Male
- Molecular Sequence Data
- Oocytes
- Origin Recognition Complex
- Sequence Alignment
- Spermatozoa
- Xenopus Proteins
- Xenopus laevis