Distinct domains of small Tims involved in subunit interaction and substrate recognition

Mailys A Vergnolle, Catherine Baud, Alexander P Golovanov, Felicity Hazel Alcock, Pierre Luciano, Lu-Yun Lian, Kostas Tokatlidis

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35 Citations (Scopus)


Tim9 and Tim10 belong to the small Tim family of mitochondrial ATP-independent chaperones. They are organised in a specific hetero-oligomeric complex (TIM10) that escorts polytopic proteins into the mitochondrial inner membrane. The contributions of the individual subunits to the assembly and function of the TIM10 complex remain poorly understood. Here, we show that substrate recognition and assembly of the complex are mediated by distinct domains of the subunits. These are unrelated to the characteristic twin CX3C motif that is present in all small Tims and ensures proper folding of the unassembled subunits. Specifically, we show that substrate recognition is achieved by the Tim10 subunit, whilst Tim9 serves a more structural role. The N-terminal domain of Tim10 is a substrate sensor whilst its C-terminal part is essential for complex formation. By contrast, both N and C-terminal domains of Tim9 are involved in the stability of the complex.
Original languageEnglish
Pages (from-to)839 - 849
Number of pages11
JournalJournal of Molecular Biology
Issue number4
Publication statusPublished - 2005
Externally publishedYes

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