Sulphonolipids are molecular determinants of gliding motility

Abstract

A variety of bacteria¹ that possess no obvious locomotor organelles are, nonetheless, able to translocate on solid surfaces (but not through liquids). In no case has the mechanism of this ‘gliding’ motility been elucidated². Our recent discovery that unusual sulphonolipids^3,4 (Fig. 1) are major cell-envelope components peculiar to the Cytophaga-Flexibacter group of gliding bacteria⁵ led us to examine whether these lipids are important in this motility. Mutants deficient in both gliding and sulphonolipid synthesis were isolated from mutagenized cultures of Cytophaga johnsonae (our laboratory strain, originally ATCC 17061). In some of these mutants, restoration of sulphonolipid content through provision of a specific biosynthetic precursor resulted in recovery of the ability to glide. The sulphonolipids are the first molecules shown to be specifically required for gliding motility (surface translocation).