Component of the TIM22 complex, a complex that mediates the import and insertion of multi-pass transmembrane proteins into the mitochondrial inner membrane. The TIM22 complex forms a twin-pore translocase that uses the membrane potential as the external driving force. Required for the stability of the TIM22 complex and functions in the assembly of the TIMM22 protein into the TIM22 complex. May facilitate cooperation between TIM22 and TOM complexes by interacting with TOMM40. Component of the TIM22 complex, which core is composed of TIMM22, associated with TIMM10 (TIMM10A and/or TIMM10B), TIMM9, AGK and TIMM29 (PubMed:27554484, PubMed:27718247, PubMed:28712724, PubMed:28712726). Interacts with TIMM10B; the interaction is direct (PubMed:27554484). Interacts with TOMM40; linking the TIM22 complex to the TOM complex (PubMed:27554484). Interacts with TIMM22 (when oxidized); the interaction is direct (PubMed:27718247).