
@article {145,
	title = {PelX is a UDP--acetylglucosamine C4-epimerase involved in Pel polysaccharide-dependent biofilm formation.},
	journal = {J Biol Chem},
	volume = {295},
	year = {2020},
	month = {2020 Aug 21},
	pages = {11949-11962},
	abstract = {<p>Pel is a GalNAc-rich bacterial polysaccharide that contributes to the structure and function of biofilms. The operon is highly conserved among diverse bacterial species, and Pel may therefore be a widespread biofilm determinant. Previous annotation of gene clusters has helped us identify an additional gene, , that is present adjacent to in \&gt;100 different bacterial species. The gene is predicted to encode a member of the short-chain dehydrogenase/reductase (SDR) superfamily, but its potential role in Pel-dependent biofilm formation is unknown. Herein, we have used Pf-5 as a model to elucidate PelX function as lacks a homologue in its gene cluster. We found that forms Pel-dependent biofilms; however, despite expression of under these conditions, biofilm formation was unaffected in a Δ strain. This observation led us to identify a paralogue, PFL_5533, which we designate here PgnE, that appears to be functionally redundant to In line with this, a Δ Δ double mutant was substantially impaired in its ability to form Pel-dependent biofilms. To understand the molecular basis for this observation, we determined the structure of PelX to 2.1 {\r A} resolution. The structure revealed that PelX resembles UDP-GlcNAc C4-epimerases. Using H NMR analysis, we show that PelX catalyzes the epimerization between UDP-GlcNAc and UDP-GalNAc. Our results indicate that Pel-dependent biofilm formation requires a UDP-GlcNAc C4-epimerase that generates the UDP-GalNAc precursors required by the Pel synthase machinery for polymer production.</p>},
	issn = {1083-351X},
	doi = {10.1074/jbc.RA120.014555},
	author = {Marmont, Lindsey S and Whitfield, Gregory B and Pfoh, Roland and Williams, Rohan J and Randall, Trevor E and Ostaszewski, Alexandra and Razvi, Erum and Groves, Ryan A and Robinson, Howard and Nitz, Mark and Parsek, Matthew R and Lewis, Ian A and Whitney, John C and Harrison, Joe J and Howell, P Lynne}
}
