Insane in the membrane: Biology of bacterial sialic acid metabolism
Sialic acids comprise a varied group of nine-carbon amino sugars that are widely distributed among mammals and higher metazoans. Commensal and pathogenic bacteria that colonise heavily sialylated niches (e.g. the mammalian respiratory tract and gut) can scavenge sialic acid from their surrounding environment and use it as a carbon, nitrogen and energy source – that is, they eat your glycoconjuates for breakfast. Sequestration and degradation of sialic acid involves specific amino sugar transporters responsible for the import into the bacterial cell and five catabolic enzymes that successively degrade sialic acid. Regulation of this pathway is achieved at the transcription level by specific repressor proteins.
In this talk I will present the first crystal structure of a sialic acid specific sodium solute symporter at 1.95 Å resolution in its outward-open conformation. Happily, this structure was determined in complex with sodium and sialic acid bound, providing insight into how this transporter mediates the movement of sialic acid across the membrane. I will then describe our structural studies on the mechanism by which the pathway is regulated at the gene level.
Overall, the work provides new data that enriches our understanding of the import and degradation of sialic acid in clinically important human bacterial pathogens.
|Date||Tuesday, 30 October 2018|
|Time||12:00pm - 1:00pm|
|Event Category||Health Sciences|
|Location||Biochemistry Seminar Room 231, Dunedin Campus|