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bioRxiv · 10.1101/2020.01.08.899336

UDP-glucose dehydrogenase Ugd in E. coli is activated by Gmd and RffD, is inhibited by CheY, and regulates swarming

Rodionova, I. A.·Zhang, Z.·Aboulwafa, M.·Saier, M. H.
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Abstract

The two most common mechanisms of polymyxin resistance in bacteria involve glycosylation of the outer membrane lipopolysaccharide (LPS) and production of the exocapsular polysaccharide, colanic acid (CA). UDP-glucose dehydrogenase, Ugd, is required for both CA biosynthesis and LPS modification. We here show that Ugd is activated by the GDP-mannose-4,6-dehydratase (Gmd, YefA, YefN), UDP-N-acetyl-D-mannosamine dehydrogenase (RffD, WecC), and ribonuclease HII (RnhB). The former two enzymes are involved in Lipid A and colanic acid biosyntheses, respectively, while RnhB cleaves RNA in RNA:DNA hybrids. Moreover, CheY inhibits the phosphorylated, activated form of Ugd (Ugd-P). Finally, Ugd is involved in the regulation of swarming, since a ugd mutant has an increased swarming rate, while Ugd overproduction inhibits swarming. Two-hybrid bacterial assays reveal direct interaction of Ugd with RssB (an anti-RpoS factor) and CheY in vivo.

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Rodionova, I. A., Zhang, Z., Aboulwafa, M., Saier, M. H.. 2020-01-09. UDP-glucose dehydrogenase Ugd in E. coli is activated by Gmd and RffD, is inhibited by CheY, and regulates swarming. https://doi.org/10.1101/2020.01.08.899336

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