This is probably because our paper describes the first case of a bacterial protein that shares striking similarities with intermediate filament proteins. Intermediate filaments, which constitute one of the three major cytoskeletal systems, were thought to be exclusively animal inventions. To find a homologous cytoskeletal system in a primitive organism such as a bacterium was unexpected and exciting.

As mentioned above, our paper describes the discovery of a bacterial cytoskeletal protein similar to intermediate filament proteins. This finding should change the way scientists view bacteria and may suggest a genetic model system in which to gain insight into intermediate filament assembly and function.

A very talented postdoc, Nora Ausmees, who now runs her own lab at Uppsala University in Sweden, identified a cell shape determinant (that we named crescentin) responsible for the characteristic crescent shape of Caulobacter crescentus. She further showed that crescentin exhibited structural, biochemical, and functional properties characteristic to eukaryotic intermediate filament proteins.

Over 30 human diseases have been linked to mutations in genes encoding intermediate filament proteins. Yet the biological properties of intermediate filaments are poorly understood, partly because of the lack of powerful genetic model systems in which to study them. The simplicity and tractability of a bacterial system may speed up intermediate filament research.