GLYCOSYLATION OF THE FLAGELLIN OF THE POLAR FLAGELLUM OF AZOSPIRILLUM-BRASILENSE, A GRAM-NEGATIVE NITROGEN-FIXING BACTERIUM

The glycosylation of the flagellin of the polar flagellum of Azospirillum brasilense Sp7 is demonstrated in several ways: (1) by a decrease in apparent M(r) after chemical deglycosylation; (2) by sugar staining after SDS-PAGE; (3) by use of a sugar-specific monoclonal antibody in immunogold labelling coupled with transmission electron microscopy. In addition, two mutant flagellins are described; they differ in glycan composition when compared with the wildtype. The glycosylation of a bacterial flagellin is unusual and has to be taken into account in the proposed model for the assembly of the flagellar filament.