Eukaryotic Origins of Replication

The origins of replication of different eukaryotic organisms vary greatly in sequence, although they usually contain numerous A–T base pairs. A multiprotein complex, the origin-recognition complex (ORC), binds to origins and unwinds the DNA in those regions.

CONCEPTS

Eukaryotic DNA contains many origins of replication. At each origin, a multiprotein origin-recognition complex binds to initiate the unwinding of the DNA.

image CONCEPT CHECK 6

What are some differences from prokaryotes in the genome structure of eukaryotic cells that affect how replication takes place?

The size of eukaryotic genomes, the linear structure of eukaryotic chromosomes, and the association of DNA with histone proteins