INVESTIGADORES
RODRIGUEZ fernanda Mariana
congresos y reuniones científicas
Título:
Characterisation of Escherichia coli TatA
Autor/es:
RODRIGUEZ FERNANDA
Lugar:
Heidelberg
Reunión:
Encuentro; EMBO Fellows Meeting; 2012
Institución organizadora:
EMBO
Resumen:
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The
twin-arginine translocation (Tat) pathway has the remarkable ability of
translocating folded proteins across membranes. This poses the mechanistic
challenge of maintaining the membrane permeability barrier to ions while
providing a pathway across the membrane for much larger proteins that differ
widely in size, shape, and surface properties. The Tat pathway is present in
bacteria, archaea, and chloroplasts. In Escherichia coli the Tat
translocase consists of three membrane proteins: TatA, TatB and TatC.
Experimental evidence suggests that a TatBC complex binds to the signal peptide
of the substrate protein. This binding event triggers the assembly of TatA with
the TatBC-substrate complex, and the substrate protein is then translocated
probably via TatA. The TatA protein is predicted to have an N-terminal
transmembrane α-helix, followed by an amphipathic helix and an unstructured
C-terminal region. TatA is currently considered to form tetramers which act as
building blocks for the higher order oligomers that mediate transport. The
higher order polymerisation of TatA is dynamic and thought to be biased by
substrate-bound TatBC. Unfortunately, very few molecular-level details of the
transport process are known and there is currently no real understanding of how
transport occurs. In this work we report the results of structural studies by
NMR spectroscopy performed on E. coli
TatA aimed at unveiling its molecular mechanism of action.