Format

Send to

Choose Destination
PLoS Genet. 2014 Dec 4;10(12):e1004869. doi: 10.1371/journal.pgen.1004869. eCollection 2014 Dec.

Transcriptional frameshifting rescues Citrobacter rodentium type VI secretion by the production of two length variants from the prematurely interrupted tssM gene.

Author information

1
Laboratoire d'Ingénierie des Systèmes Macromoléculaires (LISM), Institut de Microbiologie de la Méditerranée, CNRS - Aix-Marseille Université, UMR 7255, Marseille, France.
2
Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America.
3
Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America; Departments of Biochemistry and Microbiology, University College Cork, Cork, Ireland.

Abstract

The Type VI secretion system (T6SS) mediates toxin delivery into both eukaryotic and prokaryotic cells. It is composed of a cytoplasmic structure resembling the tail of contractile bacteriophages anchored to the cell envelope through a membrane complex composed of the TssL and TssM inner membrane proteins and of the TssJ outer membrane lipoprotein. The C-terminal domain of TssM is required for its interaction with TssJ, and for the function of the T6SS. In Citrobacter rodentium, the tssM1 gene does not encode the C-terminal domain. However, the stop codon is preceded by a run of 11 consecutive adenosines. In this study, we demonstrate that this poly-A tract is a transcriptional slippery site that induces the incorporation of additional adenosines, leading to frameshifting, and hence the production of two TssM1 variants, including a full-length canonical protein. We show that both forms of TssM1, and the ratio between these two forms, are required for the function of the T6SS in C. rodentium. Finally, we demonstrate that the tssM gene associated with the Yersinia pseudotuberculosis T6SS-3 gene cluster is also subjected to transcriptional frameshifting.

PMID:
25474156
PMCID:
PMC4256274
DOI:
10.1371/journal.pgen.1004869
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Public Library of Science Icon for PubMed Central
Loading ...
Support Center