Translocase Of Outer Mitochondrial Membrane 40 (TOMM40)

TOMM40 is the channel-forming subunit of the translocase of the mitochondrial outer membrane (TOM) complex that is essential for protein import into mitochondria.The deduced protein contains 361 amino acids. Fractionation of rat liver detected Tomm40 within the mitochondrial fraction. Extraction and antibody-accessibility studies suggested that Tomm40 is embedded within the mitochondrial membrane.Tomm40 was associated with a 400-kD complex containing the mitochondrial import receptors Tom20 and Tom22 and several smaller components. Mitochondria-targeted preproteins interacted with the Tomm40-containing complex during their transit to the mitochondrial matrix, and immunodepletion of Tomm40 caused the loss of preprotein import activity.