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. In the complex, it is required to stimulate activity of mtHSP70 (SSC1/sscA) (By similarity). Heterodimer with PAM16/pamP. Component of the PAM complex, at least composed of mtHsp70, MGE1/mgeA, tim44, PAM16/pamP, PAM17/pamQ and PAM18/pamR (By similarity). The J domain is essential for co-chaperone activity and mediates the heterodimerization with the J-like domain of PAM16. Belongs to the TIM14 family.