Formation of ORC(1-6) complex

ORC6 associates with the ORC(1-5) complex to form the ORC(1-6) complex (Ghosh et al. 2011). The association of ORC6 with the ORC(1-5) complex is weak and it frequently does not co-immunoprecipitate with the other ORC(1-5) subunits. ORC4 is the only ORC(1-5) subunit that was shown to directly bind to ORC6 (Radichev et al. 2006). Formation of the ORC(2-6) complex was demonstrated in vitro, but its biological significance, if any, is unknown (Ghosh et al. 2011). Some ORC6 mutations reported in Meier-Gorlin syndrome were shown to interfere with ORC6 incorporation into the ORC (Balasov et al. 2015).ORC6与ORC(1-5)复合体结合，共同构成ORC(1-6)复合体（Ghosh等，2011年）。ORC6与ORC(1-5)复合体的结合力较弱，且往往不与其他ORC(1-5)亚基发生共免疫沉淀。ORC4是唯一被证实能够直接结合ORC6的ORC(1-5)亚基（Radichev等，2006年）。体外实验已证明ORC(2-6)复合体的形成，但其生物学意义，若存在，尚不明确（Ghosh等，2011年）。Meier-Gorlin综合征中报道的某些ORC6突变被证实干扰了ORC6融入ORC复合体的过程（Balasov等，2015年）。