A new way out: protein localization on the bacterial cell surface via Tat and a novel Type II secretion system

The ability to move proteins out of the cytoplasm and across membranes is a key aspect of the physiology and pathogenicity of Gram‐negative bacteria. In this issue of Molecular Microbiology, Ferrandez and Condemine describe a novel protein targeting system in the enteric phytopathogen, Dickeya dadantii. The pectin lyase, PnlH, is exported by the Tat system and is somehow targeted to the outer membrane by its uncleaved N‐terminal Tat signal anchor. A novel Type II secretion system, Stt, is then responsible for moving it across the outer membrane, where it remains localized on the surface of the cell. We discuss the implications of these findings for our understanding of both the mechanisms and physiological importance of bacterial protein targeting.

[1]  G. Condemine,et al.  Novel mechanism of outer membrane targeting of proteins in Gram‐negative bacteria , 2008, Molecular microbiology.

[2]  G. Salmond,et al.  DsbA Plays a Critical and Multifaceted Role in the Production of Secreted Virulence Factors by the Phytopathogen Erwinia carotovora subsp. atroseptica* , 2008, Journal of Biological Chemistry.

[3]  C. Whitfield,et al.  Periplasmic export machines for outer membrane assembly. , 2008, Current opinion in structural biology.

[4]  Leighton Pritchard,et al.  Quorum Sensing Coordinates Brute Force and Stealth Modes of Infection in the Plant Pathogen Pectobacterium atrosepticum , 2008, PLoS pathogens.

[5]  Mechthild Pohlschröder,et al.  Haloferax volcanii twin‐arginine translocation substates include secreted soluble, C‐terminally anchored and lipoproteins , 2007, Molecular microbiology.

[6]  M. Chami,et al.  YaeT‐independent multimerization and outer membrane association of secretin PulD , 2007, Molecular microbiology.

[7]  Frank Sargent,et al.  Protein targeting by the bacterial twin-arginine translocation (Tat) pathway. , 2005, Current opinion in microbiology.

[8]  A. Filloux The underlying mechanisms of type II protein secretion. , 2004, Biochimica et biophysica acta.

[9]  J. Tommassen,et al.  Biogenesis of the Gram-negative bacterial outer membrane. , 2004, Current opinion in microbiology.

[10]  Ian K Toth,et al.  Soft rot erwiniae: from genes to genomes. , 2003, Molecular plant pathology.

[11]  M. Sandkvist Biology of type II secretion , 2001, Molecular microbiology.

[12]  Y. Liu,et al.  RecA relieves negative autoregulation of rdgA, which specifies a component of the RecA–Rdg regulatory circuit controlling pectin lyase production in Erwiniacarotovora ssp. carotovora , 1996, Molecular microbiology.

[13]  G. Condemine,et al.  Regulation of pectinolysis in Erwinia chrysanthemi. , 1996, Annual review of microbiology.