Identification of Genes Involved in the Glycosylation of Modified Viosamine of Flagellins in Pseudomonas syringae by Mass Spectrometry

• Main Authors: Yuki Ichinose, Mitsuru Yoshida, Hiroshi Ono, Tadashi Ishii, Kazuhiro Chiku, Fumiko Taguchi, Chi L. Nguyen, Mayumi Ohnishi-Kameyama, Masanobu Yamamoto
• Format: Article
• Language: English
• Published: MDPI AG 2011-10-01
• Series: Genes
• Subjects: flagellin; glycosylation; mass spectrometry; viosamine island
• Online Access: http://www.mdpi.com/2073-4425/2/4/788/

Previously we revealed that flagellin proteins in Pseudomonas syringae pv. tabaci 6605 (Pta 6605) were glycosylated with a trisaccharide, modified viosamine (mVio)-rhamnose-rhamnose and that glycosylation was required for virulence. We further identified some glycosylation-related genes, including vioA, vioB, vioT, fgt1, and fgt2. In this study, we newly identified vioR and vioM in a so-called viosamine island as biosynthetic genes for glycosylation of mVio in Pta 6605 by the mass spectrometry (MS) of flagellin glycan in the respective mutants. Furthermore, characterization of the mVio-related genes and MS analyses of flagellin glycans in other pathovars of P. syringae revealed that mVio-related genes were essential for mVio biosynthesis in flagellin glycans, and that P. syringae pv. syringae B728a, which does not possess a viosamine island, has a different structure of glycan in its flagellin protein.