Zellwand- und Aminozucker-Metabolismus von Tannerella forsythia – Einfluß auf die Adpation and das orale Habitat?
Abstract
This project aims to unravel the intriguing MurNAc-requirement of the oral pathogen T. forsythia and to elucidate the organism’s nutritional pathways for the synthesis of peptidoglycan (PGN) and other amino sugar components of its cell wall glycoconjugates. This knowledge is pivotal to the understanding of the survival strategies used by this organism to thrive in its natural habitat, the human oral cavity. The lack of the general bacterial de-novo biosynthesis pathways that yield UDP-GlcNAc from fructose-6P (GlmS/GlmU) and UDP-MurNAc (MurA/MurB) in T. forsythia suggests that proliferation of the bacterium relies on the scavenging of GlcNAc and MurNAc, or GlcNAc/ MurNAc-containing compounds that the organism likely exploits from other bacteria within biofilms and/or from glycans that it releases from host tissues. We aim to reveal the essentiality of GlcNAc besides MurNAc, for growth of T. forsythia, and the potential sources of GlcNAc and MurNAc in the natural habitat. Our previous data indicate that a PGN recycling/salvage route that leads to UDP-MurNAc is present in T. forsythia. We first will characterize the enzymes of this pathway, elucidate their essentiality, and intend to clarify connections with PGN recycling and PGN retrieval from the environment. In addition, we hypothesize that T. forsythia can modify nutritional sources for PGN precursor synthesis, such as neuraminic acid (Neu5Ac) or other amino sugar molecules. As Neu5Ac sustains growth of T. forsythia in biofilms, a connection of Neu5Ac metabolism and biofilm- specific synthetic processes are likely to occur. Given the structural similarity of Neu5Ac and nonulosonic acids (NulO), it is conceivable that there is a connection between the synthesis of glycan structures containing NulO acid, which are abundantly synthesized by T. forsythia, and PGN metabolism. We aim to unravel the possible connection of PGN biosynthesis, Neu5Ac catabolism and NulO synthesis. As the organism is directly involved in causing periodontal diseases, the anticipated results of our work may path new routes for antibacterial treatment of this widespread human health threat. Moreover we expect to deliver new insights into the particularities of the cell wall amino sugar metabolism that generally hold true for the Bacteroidetes phylum of bacteria.
Tannerella forsythia Zellwand-Metabolismus N-Acteylmuraminsäure Nonulosonsäuren Glykobiologie
Publikationen
Mitarbeiter*innen
Christina Schäffer
Univ.Prof. Dipl.-Ing. Dr.nat.techn. Christina Schäffer
christina.schaeffer@boku.ac.at
Tel: +43 1 47654-80203
Projektleiter*in
01.10.2016 - 31.12.2020