Crescentin is a protein which is a bacterial relative of the intermediate filaments found in eukaryotic cells.
Crescentin was discovered in 2009 by Christine Jacobs-Wagner in Caulobacter crescentus (now vibrioides), an aquatic bacterium which uses its crescent-shaped cells for enhanced motility.
Ausmees et al. (2003) proved that, like animal intermediate filament proteins, crescentin has a central rod made up of four coiled-coil segments.
[4] Both intermediate filament and crescentin proteins have a primary sequence including four α-helical segments along with non-α-helical linker domains.
[6] Not every researcher is convinced that it is a homolog of intermediate filaments, suggesting instead that the similarity might have arisen via convergent evolution.
Ausmees et al. continued their crescentin research by testing whether the protein could assemble into filaments in this manner in vitro.