Essential component of the TIM17:23 complex, a complex that mediates the translocation of transit peptide-containing proteins across the mitochondrial inner membrane. Component of the TIM17:23 complex at least composed of TIM23, TIM17 and TIM50. Interacts with TIM23-2. A number of isoforms are produced. According to EST sequences. Expressed in young cotyledons, roots, flowers and leaves. Up-regulated after antimycin A or rotenone treatments. Belongs to the TIM50 family. Truncated N-terminus.