Biology subjects

Gasser, V.

Publications and source records attributed to Gasser, V..

2 recordsLinked to original sources

bioRxiv2023

PvdL Orchestrates the Assembly of the Nonribosomal Peptide Synthetases Involved in Pyoverdine Biosynthesis in Pseudomonas aeruginosa.

The pyoverdine siderophore is produced by Pseudomonas aeruginosa to access iron. Its synthesis involves the complex co-ordination of four nonribosomal peptide synthetases (NRPSs), responsible for assembling the pyoverdine peptide backbone. The precise cellular organization of these NRPSs and their mechanisms of interaction remain unclear. Here, we used a combination of several single-molecule microscopy techniques to to elucidate the spatial arrangement of NRPSs within pyoverdine-producing cells. Our findings revealed that PvdL differs from the three other NRPS in term of localization and mobility patterns. PvdL is predominantly located at the inner membrane, while the other also explore the cytoplasmic compartment. Leveraging the power of multicolor single-molecule localization, we further reveal co-localization between PvdL and the other NRPSs, suggesting a pivotal role for PvdL in orchestrating the intricate biosynthetic pathway. Our observations strongly indicates that PvdL serves as a central orchestrator in the assembly of NRPSs involved in pyoverdine biosynthesis, assuming a critical regulatory function.

microbiology↗

bioRxiv2018

Macromolecular organization of the pyoverdine biosynthetic pathway in Pseudomonas aeruginosa.

The biosynthesis of the pyoverdine siderophore in Pseudomonas aeruginosa inlvolves multiple enzymes including Non-Ribosomal Peptide Synthetases (NRPS). We used in vitro single-molecule tracking and FRET-FLIM (Forster resonance energy transfer measured by fluorescence lifetime microscopy) to explore the spatial partitioning of the ornithine hydroxylase PvdA and to characterize its interactions with NRPS. The statistical description of thousands of single PvdA traces in cells using jump distance distribution analysis showed PvdA was mostly diffusing bound to large complex in the cytoplasm with a small exchangeable trapped fraction diffusing slower. FRET-FLIM clearly showed PvdA are physically interacting with the four NRPS PvdJ, PvdI, PvdL and PvdD of the pyoverdine pathway in the cellular context. Our data provide evidence for strongly organized multi-enzymatic biosynthetic complexes named siderosomes responsible for the siderophore biosynthesis. PvdA binding mode is strikingly different according to the NRPS it is interacting with suggesting PvdA binding site have co-evolved with the enzymatic active sites of NRPS.

biophysics↗