2mf7
Solution structure of the ims domain of the mitochondrial import protein TIM21 from S. cerevisiae
Structural highlights
FunctionTIM21_YEAST Essential component of the TIM23 complex, a complex that mediates the translocation of transit peptide-containing proteins across the mitochondrial inner membrane. Required to keep the TOM and the TIM23 complexes in close contact. At some point, it is released from the TOM23 complex to allow protein translocation into the mitochondrial matrix. In the complex, it acts as an antagonist of TIM50 by reducing preprotein accumulation at the TOM23 complex and promotes dissociation of the PAM complex from the TIM23 complex.[1] [2] Publication Abstract from PubMedThe presequence translocase TIM23 is a highly dynamic complex in which its subunits can adopt multiple conformations and undergo association-dissociation to facilitate import of proteins into mitochondria. Despite the importance of protein-protein interactions in TIM23, little is known about the molecular details of these processes. Using nuclear magnetic resonance spectroscopy, we characterized the dynamic interaction network of the intermembrane space domains of Tim23, Tim21, Tim50, and Tom22 at single-residue level. We show that Tim23(IMS) contains multiple sites to efficiently interact with the intermembrane space domain of Tim21 and to bind to Tim21, Tim50, and Tom22. In addition, we reveal the atomic details of the dynamic Tim23(IMS)-Tim21(IMS) complex. The combined data support a central role of the intermembrane space domain of Tim23 in the formation and regulation of the presequence translocase. Molecular Basis of the Dynamic Structure of the TIM23 Complex in the Mitochondrial Intermembrane Space.,Bajaj R, Jaremko L, Jaremko M, Becker S, Zweckstetter M Structure. 2014 Oct 7;22(10):1501-11. doi: 10.1016/j.str.2014.07.015. Epub 2014, Sep 25. PMID:25263020[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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