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Title | Structural Basis of Membrane Protein Chaperoning through the Mitochondrial Intermembrane Space. |
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Journal, issue, pages | Cell, Vol. 175, Issue 5, Page 1365-1379.e25, Year 2018 |
Publish date | Nov 15, 2018 |
Authors | Katharina Weinhäupl / Caroline Lindau / Audrey Hessel / Yong Wang / Conny Schütze / Tobias Jores / Laura Melchionda / Birgit Schönfisch / Hubert Kalbacher / Beate Bersch / Doron Rapaport / Martha Brennich / Kresten Lindorff-Larsen / Nils Wiedemann / Paul Schanda / |
PubMed Abstract | The exchange of metabolites between the mitochondrial matrix and the cytosol depends on β-barrel channels in the outer membrane and α-helical carrier proteins in the inner membrane. The essential ...The exchange of metabolites between the mitochondrial matrix and the cytosol depends on β-barrel channels in the outer membrane and α-helical carrier proteins in the inner membrane. The essential translocase of the inner membrane (TIM) chaperones escort these proteins through the intermembrane space, but the structural and mechanistic details remain elusive. We have used an integrated structural biology approach to reveal the functional principle of TIM chaperones. Multiple clamp-like binding sites hold the mitochondrial membrane proteins in a translocation-competent elongated form, thus mimicking characteristics of co-translational membrane insertion. The bound preprotein undergoes conformational dynamics within the chaperone binding clefts, pointing to a multitude of dynamic local binding events. Mutations in these binding sites cause cell death or growth defects associated with impairment of carrier and β-barrel protein biogenesis. Our work reveals how a single mitochondrial "transfer-chaperone" system is able to guide α-helical and β-barrel membrane proteins in a "nascent chain-like" conformation through a ribosome-free compartment. |
External links | Cell / PubMed:30445040 / PubMed Central |
Methods | SAS (X-ray synchrotron) |
Structure data | SASDEF2: SASDEG2: |
Source |
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