IMAGING FLAGELLA OF HALOBACTERIA BY ATOMIC-FORCE MICROSCOPY

Halobacterial flagella were adsorbed on mica and imaged with an atomic force microscope in air. Different assemblies such as large, net-like structures, and straight flagella aligned by flow were observed. The hypothesis of individual flagellar motors was confirmed by frequent ob servation of knobs at the end of single flagella. A periodic substruct ure was observed along flagellar strands with a spacing of 50-100 nm. The diameter of halobacterial flagella was determined as 11 +/- 4 nm. The influence of two different preparations on the flagellar profile, and reasons for the distortion of height and width are discussed.