Uptake of monoaromatic hydrocarbons during biodegradation by FadL channel-mediated lateral diffusion.
Somboon, K., Doble, A., Bulmer, D., Basle, A., Khalid, S., van den Berg, B.(2020) Nat Commun 11: 6331-6331
- PubMed: 33303757 
- DOI: https://doi.org/10.1038/s41467-020-20126-y
- Primary Citation of Related Structures:  
6Z34, 6Z37, 6Z38 - PubMed Abstract: 
In modern societies, biodegradation of hydrophobic pollutants generated by industry is important for environmental and human health. In Gram-negative bacteria, biodegradation depends on facilitated diffusion of the pollutant substrates into the cell, mediated by specialised outer membrane (OM) channels. Here we show, via a combined experimental and computational approach, that the uptake of monoaromatic hydrocarbons such as toluene in Pseudomonas putida F1 (PpF1) occurs via lateral diffusion through FadL channels. Contrary to classical diffusion channels via which polar substrates move directly into the periplasmic space, PpF1 TodX and CymD direct their hydrophobic substrates into the OM via a lateral opening in the channel wall, bypassing the polar barrier formed by the lipopolysaccharide leaflet on the cell surface. Our study suggests that lateral diffusion of hydrophobic molecules is the modus operandi of all FadL channels, with potential implications for diverse areas such as biodegradation, quorum sensing and gut biology.
Organizational Affiliation: 
School of Chemistry, University of Southampton, Southampton, SO17 1BJ, UK.