Origin recognition complex subunit 5 (ORC5)

Origin recognition complex subunit 5 (ORC5) is a component of the highly conserved six-subunit origin recognition complex (ORC), which is essential for the initiation of DNA replication in eukaryotic cells[1][2][3][4]. ORC5, together with the other ORC subunits (ORC1-6), forms a core platform that binds to replication origins and facilitates recruitment of additional initiation factors such as Cdc6 and the MCM (minichromosome maintenance) helicase complex[1][3][4]. ORC5 possesses an AAA+ ATPase domain—serving as a part of the ring structure encircling DNA at the origin of replication—and a winged-helix domain, both contributing to origin recognition and complex assembly[2][4]. Mutations in ORC5 can cause Meier-Gorlin syndrome 1 (a form of primordial dwarfism) and growth hormone deficiency, underlining its role in cell proliferation and development[3]. ORC5 is not currently a drug target or biomarker; its essential cellular functions mean that manipulation carries theoretical risk of interfering with normal replication and cell cycle processes[1][2][3][4].

Other names

ORC5LOrc5pORC5TPPP1R117Protein phosphatase 1 regulatory subunit 117