The hmp chemotaxis cluster regulates gliding in the filamentous cyanobacterium N ostoc punctiforme

Summary Many bacteria are capable of movement over surfaces without flagella or pili; they glide. N ostoc punctiforme is a cyanobacterium that differentiates specialized gliding filaments called hormogonia, but the mechanism underlying their movement is currently unknown. R isser et al . characterize the h ormogonia m otility and p olysaccharide ( hmp ) locus that encodes proteins homologous to well‐studied chemotaxis systems. All but one of the genes in the locus were required for gliding motility and each protein localized as a ring near the cell junction. One protein, the CheA homologue HmpE , was capable of autophosphorylation and phosphotransfer to the CheY homologue HmpB . This study reveals the hmp locus as an important regulator of gliding and highlights N . punctiforme as a model for understanding gliding motility in a complex multicellular bacterium.