Essential component of the PAM complex, a complex required for the translocation of transit peptide-containing proteins from the inner membrane into the mitochondrial matrix in an ATP-dependent manner. Recruits mitochondrial HSP70 and its co-chaperone (MGE1) to drive protein translocation into the matrix using ATP as an energy source. Component of the PAM complex, at least composed of SSC1 (mtHsp70), MGE1, TIM44, PAM16/TIM16, PAM17 and PAM18/TIM14. Forms part of the receptor complex that consists of at least 3 different proteins (TIM17, TIM23, TIM44). Belongs to the Tim44 family.