Structure of the O polysaccharide and immunochemical relationships between the lipopolysaccharides of Pseudomonas syringae pathovar tomato and pathovar maculicola

Abstract

O polysaccharides (OPS) of the lipopolysaccharides (LPS) of Pseudomonas syringae pathovar tomato GSPB 483 and pathovar maculicola IMV 381 were studied by 1 H-NMR and 13 C-NMR spectroscopy, including two-dimensional COSY, rotating-frame NOE spectroscopy (ROESY), and H-detected 1 H, 13 C heteronuclear multiple-quantum coherence (HMQC) experiments. The OPS from both strains were shown to be chemically identical. Two structurally different types of repeating units (O repeats 1 and 2) were elucidated in each OPS. The minor O repeat is a pentasaccharide having the structure 2. The same structure has been reported earlier for some other OPS of P. syringae. The major O repeat is a hexasaccharide with the novel structure 1 which is distinguished from 2 by the presence of the second lateral residue of 3-acetamido-3,6-dideoxy-D-galactose (D-Fuc3NAc) and by a different position of substitution of one of the L-rhamnose (Rha) residues in the backbone.Structural and serological diversity of OPS of strains belonging to P. syringae pv. tomato and pv. maculicola and phylogenetic relatedness of the strains are discussed. Immunochemical studies of LPS of P. syringae revealed correlation between the chemical structures of OPS and the specificity of mAbs against various strains of P. syringae [5Ϫ8]. These findings enabled us to shed some light on the molecular basis of the immunospecificity of P. syringae LPS and to infer the serogroup-specific and serotype-specific OPS-associated epitopes. One of the mAbs, Ps4e 1 (formerly Ps4a), produced against P. syringae pv. syringae (holci) IMV 8300, was shown to be specific in ELISA [8] to OPS with pentasaccharide O repeats containing four L-Rha residues in the backbone and one lateral residue of 3-acetamido-3,6-dideoxy-D-galactose (D-Fuc3NAc) (structure 3) [2]. This LPS phenotype is characterised by the serological formula O4a,4e,4e 1 . However, mAb Ps4e 1 did not

Structure of the O polysaccharides and serological classification of Pseudomonas syringae pv. porri from genomospecies 4

“…The less common serotype O8(8c) and the corresponding chemotype 8C, which has been described earlier for P. syringae pv. ribicola NCPPB 1010 [17], is characteristic of only one strain from genomospecies 4, namely the pathotype strain of P. syringae pv. oryzae, NCPPB 3683 T .…”

“…The crude LPS from strains P. syringae pv. porri NCPPB 3364 T and NCPPB 3545 cross‐reacted in ELISA with MAb Ps4a 1 , which is specific to LPS of strains from P. syringae serogroup O4 [17,29]. However, the reaction was only weak, epitope 4a 1 was not stably expressed by OPS of this strain and was absent from LPS of P. syringae pv.…”

Structure of the Lipopolysaccharide Side-chain ofPseudomonas syringaepv.tomatoStrain CFBP 2545 in Relation to O-serotype

“…Recently Knirel et al. (1998) described the common structures of the heterogeneous side‐chains of LPSs from P. syringae pv.…”

“…tomato , 140(R) and GSPB 483, have already been characterized by Knirel et al. (1993, 1998, respectively). Strain 140(R) belongs to serogroup VII in the typing scheme of Pastushenko and Simonovich (1979).…”

Structural characterization of an anticoagulant-active sulfated polysaccharide isolated from green alga Monostroma latissimum

“…The assignments for the rhamnose residues are in good agreement with the values reported for the rhamnose residues present in the O-polysaccharide chains of the lipopolysaccharide from Pseudomonas syringae pv. garcae NCPPB 2708 and P. syringae pathovar tomato GSPB 483 (Knirel, Ovod, Zdorovenko, Gvozdyak, & Krohn, 1998;Ovod, Zdorovenko, Shashkov, Kocharova, & Knirel, 2004). It is worthy to note that C-1 signal at ı 100.4 ppm was correlated with the H-1 resonance at ı 5.38 ppm, which was assigned to the (1 → 2)-linked rhamnopyranose residues with sulfation at C-3.…”