Enteric bacteria have to adapt to environmental stresses in the human gastrointestinal tract such as acid and nutrient stress, oxygen limitation and exposure to antibiotics. Membrane lipid composition has recently emerged as a key factor for stress adaptation. The E. coli ravA-viaA operon is essential for aminoglycoside bactericidal activity under anaerobiosis but its mechanism of action is unclear. Here we characterise the VWA domain-protein ViaA and its interaction with the AAA+ ATPase RavA, and find that both proteins localise at the inner cell membrane. We demonstrate that RavA and ViaA target specific phospholipids and subsequently identify their lipid-binding sites. We further show that mutations abolishing interaction with lipids restore induced changes in cell membrane morphology and lipid composition. Finally we reveal that these mutations render E. coli gentamicin-resistant under fumarate respiration conditions. Our work thus uncovers a ravA-viaA-based pathway which is mobilised in response to aminoglycosides under anaerobiosis and engaged in cell membrane regulation.

• MeSH
• adenosintrifosfatasy * metabolismus   MeSH
• aminoglykosidy * farmakologie   MeSH
• antibakteriální látky farmakologie   MeSH
• ATPázy spojené s různými buněčnými aktivitami metabolismus   MeSH
• Escherichia coli * účinky léků   enzymologie   MeSH
• fosfolipidy MeSH
• fumaráty MeSH
• gentamiciny MeSH
• kyslík metabolismus   MeSH
• membránové lipidy MeSH
• proteiny z Escherichia coli * metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adenosintrifosfatasy * MeSH
• aminoglykosidy * MeSH
• antibakteriální látky MeSH
• ATPázy spojené s různými buněčnými aktivitami MeSH
• fosfolipidy MeSH
• fumaráty MeSH
• gentamiciny MeSH
• kyslík MeSH
• membránové lipidy MeSH
• proteiny z Escherichia coli * MeSH
• RavA protein, E coli MeSH Prohlížeč
• ViaA protein, E coli MeSH Prohlížeč

Cardiolipin and phosphatidylglycerol are anionic phospholipids localized to the inner mitochondrial membrane. In this study, it is demonstrated by fluorescence and transmission electron microscopy that atp2.1pgs1Δ mutant mitochondria lacking anionic phospholipids contain fragmented and swollen mitochondria with a completely disorganized inner membrane. In the second part of this study, it was shown that the temperature sensitivity of the atp2.1pgs1Δ mutant was not suppressed by the osmotic stabilizer glucitol but by glucosamine, a precursor of chitin synthesis. The atp2.1pgs1Δ mutant was hypersensitive to Calcofluor White and caffeine, resistant to Zymolyase, but its sensitivity to caspofungin was the same as the strains with the standard PGS1 gene. The distribution of chitin in the mutant cell wall was impaired. The glucan level in the cell wall of the atp2.1pgs1Δ mutant was reduced by 4-8 %, but the level of chitin was almost double that in the wild-type strain. The cell wall of the atp2.1pgs1Δ mutant was about 20 % thinner than the wild type, but its morphology was not significantly altered.

• MeSH
• aerobióza MeSH
• buněčná stěna chemie   ultrastruktura   MeSH
• delece genu MeSH
• fluorescenční mikroskopie MeSH
• fosfolipidy nedostatek   MeSH
• glukany analýza   MeSH
• Kluyveromyces cytologie   genetika   růst a vývoj   metabolismus   MeSH
• mitochondrie ultrastruktura   MeSH
• teplota MeSH
• transmisní elektronová mikroskopie MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fosfolipidy MeSH
• glukany MeSH