Northampton Electronic Collection of Theses and Research

Essential cytoplasmic domains in the Escherichia coli TatC protein

Allen, S. C. H., Barrett, C. M., Ray, N. and Robinson, C. (2002) Essential cytoplasmic domains in the Escherichia coli TatC protein. The Journal of Biological Chemistry. 277(12), pp. 10362-10366. 0021-9258.

Item Type: Article
Abstract: The twin-arginine translocation (Tat) system mediates the transport of proteins across the bacterial plasma membrane and chloroplast thylakoid membrane. Operating in parallel with Sec-type systems in these membranes, the Tat system is completely different in both structural and mechanistic terms, and is uniquely able to catalyze the translocation of fully folded proteins across coupled membranes. TatC is an essential, multispanning component that has been proposed to form part of the binding site for substrate precursor proteins. In this study we have tested the importance of conserved residues on the periplasmic and cytoplasmic face of the Escherichia coli protein. We find that many of the mutations on the cytoplasmic face have little or no effect. However, substitution at several positions in the extreme N-terminal cytoplasmic region or the predicted first cytoplasmic loop lead to a significant or complete loss of Tat-dependent export. The mutated strains are unable to grow anaerobically on trimethylamine N-oxide minimal media and are unable to export trimethylamine-N-oxide reductase (TorA). The same mutants are completely unable to export a chimeric protein, comprising the TorA signal peptide linked to green fluorescent protein, indicating that translocation is blocked rather than cofactor insertion into the TorA mature protein. The data point to two essential cytoplasmic domains on the TatC protein that are essential for export
Subjects: Q Science > QP Physiology > QP501 Animal biochemistry > QP514.2 Biochemistry
Q Science > QR Microbiology > QR75 Bacteria
Creators: Allen, Stuart C H, Barrett, C M, Ray, N and Robinson, C
Publisher: American Society for Biochemistry and Molecular Biology
Faculties, Divisions and Institutes: University Faculties, Divisions and Research Centres - OLD > Faculty of Health & Society > Sports, Exercise & Life Sciences
Faculties > Faculty of Health & Society > Sports, Exercise & Life Sciences
Date: 22 March 2002
Date Type: Publication
Page Range: pp. 10362-10366
Journal or Publication Title: The Journal of Biological Chemistry
Volume: 277
Number: 12
Language: English
ISSN: 0021-9258
Status: Published / Disseminated

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