Reductive evolution in outer membrane protein biogenesis has not compromised cell surface complexity in Helicobacter pylori

• Main Authors: Webb, Chaille T., Chandrapala, Dilini, Oslan, Siti Nurbaya, Bamert, Rebecca S., Grinter, Rhys D., Dunstan, Rhys A., Gorrell, Rebecca J., Song, Jiangning, Strugnell, Richard A., Lithgow, Trevor, Kwok, Terry
• Format: Article
• Language: English
• Published: John Wiley & Sons 2017
• Online Access: http://psasir.upm.edu.my/id/eprint/62930/1/Reductive%20evolution%20in%20outer%20membrane%20protein%20biogenesis.pdf; http://psasir.upm.edu.my/id/eprint/62930/; https://onlinelibrary.wiley.com/doi/epdf/10.1002/mbo3.513
• Institution: Universiti Putra Malaysia

Helicobacter pylori is a gram-negative bacterial pathogen that chronically inhabits the human stomach. To survive and maintain advantage, it has evolved unique host-pathogen interactions mediated by Helicobacter-specific proteins in the bacterial outer membrane. These outer membrane proteins (OMPs) are anchored to the cell surface via a C-terminal β-barrel domain, which requires their assembly by the β-barrel assembly machinery (BAM). Here we have assessed the complexity of the OMP C-terminal β-barrel domains employed by H. pylori, and characterized the H. pyloriBAM complex. Around 50 Helicobacter-specific OMPs were assessed with predictive structural algorithms. The data suggest that H. pylori utilizes a unique β-barrel architecture that might constitute H. pylori-specific Type V secretions system. The structural and functional diversity in these proteins is encompassed by their extramembrane domains. Bioinformatic and biochemical characterization suggests that the low β-barrel-complexity requires only minimalist assembly machinery. The H. pylori proteins BamA and BamD associate to form a BAM complex, with features of BamA enabling an oligomerization that might represent a mechanism by which a minimalist BAM complex forms a larger, sophisticated machinery capable of servicing the outer membrane proteome of H. pylori.