RMI1
Description
The RMI1 (RecQ mediated genome instability 1) is a protein-coding gene located on chromosome 9.
RMI1 (RecQ-mediated genome instability protein 1) is a human protein encoded by the RMI1 gene. Mutations in RMI1 are associated with Bloom-Syndrome like disorder, particularly observed in individuals with microcephalic dwarfism. RMI1 is a component of the Bloom Syndrome Complex and contains two OB (oligonucleotide binding) domains. The OB1 domain binds to Topoisomerase III alpha, while the OB2 domain interacts with RMI2 within the Bloom Syndrome complex and FANCM of the Fanconi Anaemia pathway. An insert within the OB1 domain of RMI1 integrates into the catalytic center of Topoisomerase III alpha, which is essential for the enzyme's optimal activity during DNA repair and homologous recombination. In budding yeast, RMI1 forms a heterodimer with TOP3 (a type I topoisomerase) during meiosis. This heterodimer facilitates the passage of one DNA single strand through another. The TOP3-RMI1 heterodimer associates with Sgs1 (Bloom helicase ortholog) to form a complex that catalyzes the dissolution of double Holliday junctions.
RMI1 is an essential component of the RMI complex, which plays a crucial role in processing homologous recombination intermediates to limit DNA crossover formation in cells. It facilitates TOP3A binding to double Holliday junctions (DHJ), leading to the stimulation of TOP3A-mediated dissolution. RMI1 is also required for BLM phosphorylation during mitosis and contributes to the stability of both BLM and TOP3A within the BLM complex.
RMI1 is also known as BLAP75, C9orf76, FAAP75.
