The structure of an alternative wall teichoic acid produced by a Lactobacillus plantarum WCFS1 mutant contains a 1,5-linked poly(ribitol phosphate) backbone with 2-α-d-glucosyl substitutions

A tagF1–tagF2 deletion mutant of Lactobacillus plantarum lacks poly(glycerol phosphate) polymerase activity required for glycerol-type wall teichoic acid (WTA) biosynthesis. The mutant activates an alternative genetic locus, tarIJKL, encoding the enzymes for nucleotide activation and incorporation of ribitol in the WTA backbone polymer. This alternative ribitol-type WTA backbone and its repeating unit were isolated and characterized by HPAEC, UPLC-MS, NMR spectroscopy, and MALDI-TOF MS, using synthetic molecules as references. The structure was established as 1,5-linked poly(ribitol phosphate) which was substituted at the C-2 hydroxyl group of the ribitol residue with α-d-glucosyl at a frequency of 28%.