initiation of replication

DnaA accumulates during growth and then triggers the initiation of replication.

The CtrA protein, in contrast, acts to block initiation of replication, so it must be removed from the cell before chromosome replication can begin.

Mutations in this protein in budding yeast, and in its homolog in fission yeast block initiation of replication.

The C-terminus region is thought to provide a checkpoint before entering anaphase, provide stability to the holoenzyme, and add proteins to the holoenzyme necessary for initiation of replication.

The gene product is responsible for mitochondrial gene expression as well as for providing RNA primers for initiation of replication of the mitochondrial genome.

In a traditional C. fasciculata kDNA network, initiation of replication is promoted by the unlinking of kDNA minicricles via topoisomeraseII.

In prokaryotic DNA replication regulation focuses on the binding of the DnaA initiator protein to the DNA, with initiation of replication occuring multiple times during one cell cycle.

Thus, ATR-Chk1 activity further prevents potential replication problems at the level of single replication origins by inhibiting initiation of replication throughout the genome, until the signaling cascade maintaining cell-cycle arrest is turned off.

One possibility is that these different compartments within the nucleus, established and maintained without the aid of membranes or physical barriers, set thresholds for the initiation of replication so that the more accessible regions are the first to replicate.

The ORC is a six-subunit, Orc1p-6, protein complex that selects the replicative origin sites on DNA for initiation of replication and ORC binding to chromatin is regulated through the cell cycle.

This hemimethylated DNA is recognized by the protein SeqA, which binds and sequesters the origin sequence; in addition, DnaA (required for initiation of replication) binds less well to hemimethylated DNA.

It is able to anneal to single-stranded DNA (ssDNA) as well as melt small fragments of dsDNA; its role is to destabilize duplex DNA during initiation of replication.

Inactivation of temperature sensitive mutants of any of the Mcm proteins in "S. cerevisiae" caused DNA replication to halt if inactivation occurred during S phase, and prevented initiation of replication if inactivation occurred earlier.

A certain number of DnaA proteins are also required for DNA replication - each time the origin is copied, the number of binding sites for DnaA doubles, requiring the synthesis of more DnaA to enable another initiation of replication.