Promotie
Another Brick in the Wall: The role of the actinobacterial cell wall in antibiotic resistance, phylogeny and development
- Datum
- woensdag 20 maart 2019
- Tijd
- Locatie
-
Academiegebouw
Rapenburg 73
2311 GJ Leiden
Samenvatting
Streptomyces are multicellular, Gram-positive bacteria in the phylum of actinobacteria which produce a high amount of bioactive natural products of which the expression is tightly coordinated with the life cycle. This thesis shows the identification of S. roseifaciens, a novel species with an uncommon, verticillate spore morphology and a unique household of SsgA-like proteins. Analyses of the peptidoglycan composition show that S. coelicolor show a pattern of 3-3 cross-linking befitting a tip-growing organism and change in composition between vegetative mycelium and spores. Kitasatosporae carry meso-DAP in the peptidoglycan of vegetative mycelium and LL-DAP in the peptidoglycan of spores. In line with this difference, the peptidoglycan architecture of these two growth stages undergoes such radical changes that they would seem to be from different species. S. coelicolor is naturally vancomycin resistant, but the addition of D-alanine and a disruption in a single gene increases vancomycin sensitivity by a thousandfold. A knockout mutant of the alanine racemase, alr, requires exogenous addition of D-alanine. The Alr crystal structure of S. coelicolor and the D-cycloserine producer S. lavendulae were compared as to look for possible mechanisms for D-cycloserine resistance.
Promotoren
- Prof.dr. G.P. van Wezel
- Prof.dr. T. Hankemeier
Bijwonen
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Persvragen
Maarten Muns, adviseur wetenschapscommunicatie Universiteit Leiden
m.a.muns@bb.leidenuniv.nl
071 527 3282