Figure 9 .

Assembly feedback control of Cox1 synthesis by Mss51 activities as a translational activator and assembly factor. Mitochondria translation of the COX1 mRNA is activated by the mRNA-specific activators Pet309 and Mss51 [Mss51 is associated with Hsp70 (Ssc1) throughout]. Synthesis of a new Cox1 polypeptide nucleates an early assembly intermediate containing Mss51 and the assembly factors Cox14 and Coa3. As additional assembly factors associate with newly synthesized Cox1, Mss51 is released from the assembly intermediates and is then available to initiate additional Cox1 synthesis.