Award details

Structure-function studies of the Tat protein translocation channel

Reference	BB/C516179/1
Principal Investigator / Supervisor	Professor Helen Saibil
Co-Investigators / Co-Supervisors
Institution	Birkbeck College
Department	Biological Sciences
Funding type	Research
Value (£)	229,473
Status	Completed
Type	Research Grant
Start date	15/03/2006
End date	14/03/2009
Duration	36 months

Abstract

The membrane proteins TatA, TatB and TatC are the essential components of the Tat transport pathway. TatA and TatBC form separate, highly oligomeric, complexes. The TatBC complex functions as a receptor for the substrate protein. TatA is proposed to form the transmembrane protein translocation channel. This suggestion is supported by our recent low resolution structure of the TatA complex, obtained by negative stain electron microscopy, which shows a variable-diameter ring occluded at one end by a lid structure. This project aims to: (a) continue our studies of the structures of the Tat complexes by electron microscopy. Obtain structures for the TatBC complex by particle electron microscopy methods. Correlate structural features of the TatA complex with protein domains by truncation analysis. Produce higher resolution structures of TatA using single particle cryo-electron microscopy. (b) Carry out a multidisciplinary programme of research to test, exploit and expand the structural and mechanistic insights arising from our low resolution structure of the TatA complex. We will: Test models of channel operation by assessing the oligomeric state of native TatA molecules and examining whether TatA complexes exhibit transport-dependent exchange of TatA protomers. Assess using electron microscopy, atomic force microscopy and electrophysiological techniques whether the TatA complex contains an aqueous channel in the native membrane environment. Attempt to identify regions of the TatA protein that must move to allow Tat transport to occur. To do this we will analyse the effects of introduced disulfide bonds (identified in other work) on in vitro protein transport. Joint with BB/C516144/1

Summary

unavailable

Committee	Closed Committee - Biomolecular Sciences (BMS)
Research Topics	Microbiology, Structural Biology
Research Priority	X – Research Priority information not available
Research Initiative	X - not in an Initiative
Funding Scheme	X – not Funded via a specific Funding Scheme

Associated awards:

BB/C516144/1 Structure-function studies of the Tat protein translocation channel

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