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Evolution of paralogous multicomponent systems for site-specific O-sialylation of flagellin in Gram-negative and Gram-positive bacteria

ABSTRACT: Many bacteria decorate flagellin with sialic acid-like sugars such as pseudaminic acid (Pse) by O-glycosylation on serine or threonine residues. Evidence for sufficiency of sialylation by a conserved flagellin glycosyltransferase (fGT) system is lacking, presumably because of (a) missing component(s). Here, we reconstituted two Maf-type fGTs from the Gram-negative bacterium Shewanella oneidensis MR-1 in a heterologous host producing a Pse donor sugar. While Maf-1 is sufficient for flagellin glycosylation, Maf-2 reconstitution requires a newly identified, cis-encoded and conserved specificity factor GlfM, predicted to form a four-helix bundle. While GlfM binds Maf-2 to form a ternary complex with flagellin, the C-terminal tetratricopeptide repeat (TPR) domain of Maf-1 confers flagellin acceptor and O-glycosylation specificity at preferred serine residues. GlfM from Gram-negative and Gram-positive bacteria are functional, providing evidence for convergent evolution of specialized flagellin modification systems with acceptor serine selectivity, while also shaping the evolution of bacterial tripartite and bipartite O-glycosylation systems.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Caulobacter Crescentus (strain Na1000 / Cb15n) Shewanella Oneidensis (strain Mr-1)

SUBMITTER: Jovelyn Unay

LAB HEAD: Patrick Viollier

PROVIDER: PXD051215 | Pride | 2024-06-18

REPOSITORIES: Pride

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			Action	DRS
	20221104_002_S421340_SoWT-flaA_A_20221104174809.raw.byspec2	Raw
	20221104_002_S421340_SoWT-flaA_A_20221104174809.raw_20221111_Byonic_WC_T_130_900_semi.byparms	Raw
	20221104_002_S421340_SoWT-flaA_A_20221104174809.raw_20221111_Byonic_WC_T_130_900_semi.byrslt	Raw
	20221104_002_S421340_SoWT-flaA_A_20221104174809.raw_20221111_Byonic_WC_T_130_900_semi.mgf	Mgf
	20221104_002_S421340_SoWT-flaA_A_20221104174809.raw_20221111_Byonic_WC_T_130_900_semi.mzid.gz	Mzid

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Evolution of paralogous multicomponent systems for site-specific O-sialylation of flagellin in Gram-negative and Gram-positive bacteria

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