DNA Replication in Eukaryotes

Flashcards covering key vocabulary and concepts related to DNA replication in eukaryotes.

Replicon

Independent units of replication in DNA.

Bidirectional Replication

Type of replication where polymerase moves along both strands in both directions.

Unidirectional Replication

Type of replication where polymerase replicates both strands in one direction away from the origin.

DNA polymerase alpha (Pol a)

Starts DNA synthesis, tightly associated with DNA primase but does not have proofreading activity.

DNA polymerase epsilon (Pol ε)

Responsible for leading strand synthesis and has 3'→5' proofreading activity.

DNA polymerase delta (Pol δ)

Responsible for lagging strand synthesis and corrects mismatches introduced during primer extension.

Origin Recognition Complex (ORC)

A complex that binds to ARS sequences and identifies potential replication origins.

Autonomously Replicating Sequences (ARS)

Defined DNA sequences that function as origins of replication in yeast.

Cyclin-dependent kinases (CDKs)

Enzymes that regulate the cell cycle progression by phosphorylating target proteins.

Geminin

A protein expressed in late G1 and S-phase that blocks new loading of helicase.

Competency to fire

The ability of an origin to form a successful pre-replication complex and initiate replication.

Pre-replication complex (pre-RC)

A complex that marks an origin as ready to replicate, made up of ORC, Cdc6, Cdt1, and Mcm2-7.

Checkpoint kinase 1 (Chk1)

A protein that helps regulate the cell cycle response to DNA damage and replication stress.

Replication foci

Discrete nuclear sites where DNA synthesis is actively occurring during S phase.

Histone modifications

Chemical changes to histone proteins that control gene expression and need to be copied during DNA replication.

POLG gene

Gene that encodes for DNA polymerase gamma, essential for duplicating mitochondrial DNA.