ORC4 : origin recognition complex subunit 4
Description
The ORC4 (origin recognition complex subunit 4) is a protein-coding gene located on chromosome 2.
The ORC4 gene provides instructions for producing a protein vital for DNA replication, the process of copying a cell's DNA before division. This protein, ORC4, is part of the origin recognition complex (ORC), which is made up of six proteins (ORC1-ORC6). ORC binds to specific DNA regions called origins of replication, where DNA copying begins. This binding attracts other proteins to form the pre-replication complex, initiating replication. This tightly regulated process, called replication licensing, ensures DNA replication occurs only once per cell division, essential for cell growth. ORC4 also binds to heterochromatin, a tightly packed form of DNA containing few genes. Heterochromatin plays a role in controlling gene activity and maintaining chromosome structure, but the effect of ORC binding on it is unclear.
ORC4 is a subunit of the origin recognition complex (ORC), which plays a critical role in DNA replication. It binds to specific DNA sequences known as origins of replication, initiating the process of DNA copying. This binding requires ATP and the specific DNA sequences that define these origins are still under investigation. ORC4 is essential for assembling the pre-replication complex, which is necessary for the initiation of DNA replication. Additionally, ORC4 interacts with histone H3 and H4 trimethylation marks (H3K9me3, H3K27me3, and H4K20me3).
ORC4 is also known as ORC4L, ORC4P.
