Essential core component of the TIM22 complex, a complex that mediates the import and insertion of multi-pass transmembrane proteins into the mitochondrial inner membrane. In the TIM22 complex, it constitutes the voltage-activated and signal-gated channel. Forms a twin-pore translocase that uses the membrane potential as external driving force in 2 voltage-dependent steps (By similarity). Component of the TIM22 complex, whose core is composed of tim-22, associated with the 70 kDa heterohexamer. In most cases, the 70 kDa complex is composed of tim-9/tin-9.1 and tim-10/tin-10 (By similarity). Belongs to the Tim17/Tim22/Tim23 family.