mitochondrial import inner membrane translocase subunit TIM8B; deafness dystonia protein 2; DDP-like protein (TIMM8B, TIM8B)

Function

• mitochondrial intermembrane chaperone (putative)
• participates in the import & insertion of some multi-pass transmembrane proteins into the mitochondrial inner membrane
• also required for the transfer of beta-barrel precursors from the TOM complex to the sorting & assembly machinery (SAM complex) of the outer mitochondrial membrane
• acts as a chaperone-like protein that protects the hydrophobic precursors from aggregation & guides them through the mitochondrial intermembrane space (putative)
• forms heterohexamer; of 3 copies of TIMM8B & 3 copies of TIMM13, named soluble 70 kD complex (putative)
• associates with the TIM22 complex, whose core is composed of TIMM22

Structure

• the twin CX3C motif contains 4 conserved Cys that form 2 disulfide bonds in the mitochondrial intermembrane space
• during transit of TIMM8B from cytoplasm into mitochondrion, the Cys probably coordinate Zn+2, thus preventing folding & allowing its transfer across the mitochondrial outer membrane
• belongs to the small Tim family

Compartment

• mitochondrial inner membrane, intermembrane side (putative)

Expression

• ubiquitous
• highest expression in heart, kidney, liver & skeletal muscle

More general terms

• protein subunit
• mitochondrial membrane protein

Component of

• mitochondrial import inner membrane translocase subunit (TIM, translocase of inner mitochondrial membrane, mitochondrial protein importer)

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:2652
• OMIM: https://mirror.omim.org/entry/606659
• UniProt: http://www.uniprot.org/uniprot/Q9Y5J9.html