Assembly of the secretion pores GspD, Wza and CsgG into bacterial outer membranes does not require the Omp85 proteins BamA or TamA
Rhys A Dunstan, Iain D Hay, Jonathan J Wilksch, Ralf B Schittenhelm, Anthony W Purcell, Joan Clark, Adam Costin, Georg Ramm, Richard A Strugnell, Trevor Lithgow
MOLECULAR MICROBIOLOGY | WILEY-BLACKWELL | Published : 2015
In Gram-negative bacteria, β-barrel proteins are integrated into the outer membrane by the β-barrel assembly machinery, with key components of the machinery being the Omp85 family members BamA and TamA. Recent crystal structures and cryo-electron microscopy show a diverse set of secretion pores in Gram-negative bacteria, with α-helix (Wza and GspD) or β-strand (CsgG) transmembrane segments in the outer membrane. We developed assays to measure the assembly of three distinct secretion pores that mediate protein (GspD), curli fibre (CsgG) and capsular polysaccharide (Wza) secretion by bacteria and show that depletion of BamA and TamA does not diminish the assembly of Wza, GspD or CsgG. Like the..View full abstract
Awarded by Australian Research Council (ARC)
Awarded by National Health and Medical Research Council (NHMRC)
We thank Christopher Stubenrauch, Chaille Webb, Eva Heinz, Matthew Belousoff and Daniel Wall for expert advice and critical comments on the manuscript. The project was supported by the Australian Research Council (ARC) (FL130100038, to TL) and the National Health and Medical Research Council (NHMRC) (Program Grant 606788, to RAS and TL). RAD is a recipient of a Monash Research Scholarship, AWP is an NHMRC Senior Research Fellow and TL is an ARC Australian Laureate Fellow. The authors have no conflicts of interest to declare.