[SCAN] Peptidoglycan branching enzymes – janitors in bacterial metabolism?
Sérgio Filipe
| When |
09 Dec, 2020
from
12:00 pm to 01:00 pm |
|---|---|
| Contact Name | Rita Abranches |
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Peptidoglycan (PGN) surrounds bacterial cells and provides protection to the extreme osmotic forces they are subjected to. It is a heterogeneous polymer of glycan chains, crosslinked by short peptides of variable length and amino acid composition. PGN maybe be linear, if crosslinking between two muropeptides is direct, or branched, if crosslinking occurs via a crossbridge.
The synthesis of the crossbridge in branched PGNs takes place, in most cases, at the membrane and is dependent on a specific set of enzymes that belong to the FemXAB/MurMN family. These enzymes are non-ribosomal peptidyl transferases and use specific aminoacyl-tRNAs as amino acid donors to produce the peptide crossbridge.
The presence of branched PGN is essential in many Gram-positive bacteria, but not in Streptococcus pneumoniae, a Gram-positive bacterium of clinical relevance.
In this seminar, I will describe how PGN composition influences pneumococcal metabolism and present evidence that supports an intriguing role of PGN as a drainage system to ensure the elimination of particular toxic elements.
ITQB NOVA Virtual Auditorium
