Flagellar proteins of Phaeobacter inhibens DSM 17395 and selected mutants

Flagellar motility is crucial for the swim-and-stick lifestyle of Rhodobacterales and plays an important role for bacterial-algal interactions. This alphaproteobacterial order contains three distinct types of flagellar gene clusters (FGCs) for the formation of a functional flagellum. Swimming of the marine model organism Phaeobacter inhibens DSM 17395 (Roseobacteraceae) is mediated by the archetypal fla1 flagellum. Screening of 13,000 transposon mutants on soft agar plates revealed that 40 genes, including four genes encoding conserved but not yet characterized proteins (CP1-4) within the FGC, are essential for motility. Exoproteome analyses of P. inhibens DSM 17395 wildtype and 10 transposon mutants, i.e., ΔmotB, ΔCP1, ΔCP2, ΔCP3, ΔCP4, ΔfliK, ΔfliI, ΔflgH, ΔctrA, Δ65kb plasmid were conducted.