Essential component of the TIM17:23 complex, a complex that mediates the translocation of transit peptide-containing proteins across the mitochondrial inner membrane. Links the inner and outer membranes (By similarity). Component of the TIM17:23 complex at least composed of TIM23, TIM17 and TIM50. The complex interacts with the TIM44 component of the PAM complex (By similarity). Expressed in roots, flowers, cotyledons and leaves. Peak of expression during cotyledon development. Belongs to the Tim17/Tim22/Tim23 family.