The TOM37 protein is one of the outer membrane proteins that make up the TOM complex for guiding cytosolic mitochondrial beta-barrel proteins from the cytosol across the outer mitochondrial membrane into the intra-membrane space. In conjunction with TOM70 it guides peptides without an MTS into TOM40, the protein that forms the passage through the outer membrane [1]. It has homology with Metaxin-1, also part of the outer mitochondrial membrane beta-barrel protein transport complex [2].

1: TOM20 and the heartbreakers: evidence for the role of mitochondrial transport proteins in cardioprotection. Bowers M, Ardehali H; J Mol Cell Cardiol. 2006;41:406-409. PMID:16890951

2: Functional definition of outer membrane proteins involved in preprotein import into mitochondria. Lister R, Carrie C, Duncan O, Ho LH, Howell KA, Murcha MW, Whelan J; Plant Cell. 2007;19:3739-3759. PMID:17981999