Midasin AAA ATPase 1 (MDN1)

Midasin AAA ATPase 1 (MDN1) is a massive, essential ATPase enzyme that functions as a nuclear chaperone for the large subunit of the eukaryotic ribosome. MDN1 utilizes ATP hydrolysis to power ATP-fueled motions that physically restructure and remove assembly factors from pre-60S ribosomal particles, a key step in ribosome biogenesis. Structurally, MDN1 contains a ring-shaped AAA ATPase domain, extended linking domains, and a C-terminal MIDAS (Metal Ion-dependent Adhesion Site) domain. The MIDAS domain is responsible for binding substrate proteins (assembly factors), transmitting mechanical force to facilitate their removal via dynamic conformational coupling with the AAA ring. MDN1 is not a druggable target in current pharmacology but is studied via chemical inhibitors like Rbin-1 to dissect ribosome assembly mechanisms. Dysfunction or mutation of MDN1 can disrupt ribosome formation and is implicated in rare human disorders, but it is not an established therapeutic or disease target

Other names

MidasinKIAA0301Dynein-related AAA-ATPase MDN1MIDAS-containing proteinRea1midasin homologMdn1

Noncompetitive, allosteric inhibition of ATPase activity by Rbin-1 (binds and induces conformational change, affecting the coupling between the AAA ring and the MIDAS domain; used only in research, not a therapeutic mechanism)