 |
CEntre de Recherches sur les MAcromolécules Végétales |  |
Journal articles
Misincorporation of Galactose by Chondroitin Synthase of Escherichia coli K4: From Traces to Synthesis of Chondbiuronan, a Novel Chondroitin-Like Polysaccharide
Abstract : Chondroitin synthase KfoC is a bifunctional enzyme which polymerizes the capsular chondroitin backbone of Escherichia coli K4, composed of repeated β3N-acetylgalactosamine (GalNAc)-β4-glucuronic acid (GlcA) units. Sugar donors UDP-GalNAc and UDP-GlcA are the natural precursors of bacterial chondroitin synthesis. We have expressed KfoC in a recombinant strain of Escherichia coli deprived of 4-epimerase activity, thus incapable of supplying UDP-GalNAc in the bacterial cytoplasm. The strain was also co-expressing mammal galactose β-glucuronyltransferase, providing glucuronyl-lactose from exogenously added lactose, serving as a primer of polymerization. We show by the mean of NMR analyses that in those conditions, KfoC incorporates galactose, forming a chondroitin-like polymer composed of the repeated β3-galactose (Gal)-β4-glucuronic acid units. We also show that when UDP-GlcNAc 4-epimerase KfoA, encoded by the K4-operon, was co-expressed and produced UDP-GalNAc, a small proportion of galactose was still incorporated into the growing chain of chondroitin.
https://hal.archives-ouvertes.fr/hal-03455592
Contributor : Sophie Drouillard Connect in order to contact the contributor
Submitted on : Monday, November 29, 2021 - 5:25:32 PM
Last modification on : Thursday, December 2, 2021 - 2:14:02 PM
Contributor : Sophie Drouillard Connect in order to contact the contributor
Submitted on : Monday, November 29, 2021 - 5:25:32 PM
Last modification on : Thursday, December 2, 2021 - 2:14:02 PM
File
2020 biomolecules 10 1667 chod...
Publisher files allowed on an open archive