AAA proteases with catalytic sites on opposite membrane surfaces comprise a proteolytic system for the ATP-dependent degradation of inner membrane proteins in mitochondria.

摘要: The mechanism of selective protein degradation membrane proteins in mitochondria has been studied employing a model that is subject to rapid proteolysis within the inner membrane. Protein was mediated by two different proteases: (i) m-AAA protease, protease complex consisting multiple copies ATP-dependent metallopeptidases Yta1Op (Afg3p) and Yta12p (Rcalp); (ii) Ymelp (Ytallp) also embedded Ymelp, highly homologous Yta12p, forms approximately 850 kDa exerts metallopeptidase activity. While exposes catalytic sites mitochondrial matrix, active intermembrane space. therefore termed 'i-AAA protease'. Analysis proteolytic fragments indicated cleavage polypeptide at outer surface membrane-spanning domain. Thus, AAA proteases with their on opposite surfaces constitute novel system for mitochondria.