Electrostatics and Intrinsic Disorder Drive Translocon Binding of the SRP Receptor FtsY |
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| Authors: | Dr. Nils‐Alexander Lakomek Dr. Albena Draycheva Dr. Thomas Bornemann Prof. Dr. Wolfgang Wintermeyer |
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| Affiliation: | 1. Department of NMR-based Structural Biology, Max-Planck Institute for Biophysical Chemistry, G?ttingen, Germany;2. ETH Zurich, Department of Chemistry and Applied Biosciences (D-CHAB), Laboratory of Physical Chemistry (LPC), Zurich, Switzerland;3. Max-Planck Institute for Biophysical Chemistry, Department of Physical Biochemistry, G?ttingen, Germany |
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| Abstract: | Integral membrane proteins in bacteria are co‐translationally targeted to the SecYEG translocon for membrane insertion via the signal recognition particle (SRP) pathway. The SRP receptor FtsY and its N‐terminal A domain, which is lacking in any structural model of FtsY, were studied using NMR and fluorescence spectroscopy. The A domain is mainly disordered and highly flexible; it binds to lipids via its N terminus and the C‐terminal membrane targeting sequence. The central A domain binds to the translocon non‐specifically and maintains disorder. Translocon targeting and binding of the A domain is driven by electrostatic interactions. The intrinsically disordered A domain tethers FtsY to the translocon, and because of its flexibility, allows the FtsY NG domain to scan a large area for binding to the NG domain of ribosome‐bound SRP, thereby promoting the formation of the quaternary transfer complex at the membrane. |
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| Keywords: | biophysics intrinsically disordered proteins NMR spectroscopy protein– protein interactions translocon |
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