Talk abstracts
Talk on Thursday 03:30-03:45pm submitted by Berkay Selcuk
Ancestral Components of Bacterial Flagellum
Berkay Selcuk (Biophysics Graduate Program, Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, USA), Ekaterina P. Andrianova (Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, USA), Morgan Beeby (Molecular Biology Institute, University of California, Los Angeles UCLA, Box 951570, Los Angeles, CA 90095, USA.), Daniel B. Kearns, Marc Erhardt (Max Planck Unit for the Science of Pathogens, Berlin, Germany), Igor Jouline (Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio, USA)
Abstract:
The bacterial flagellum is a sophisticated molecular machine and a key model for understanding how complex cellular structures originate and diversify. Previous work proposed a core of 24 ancestral flagellar genes, but this set is insufficient to build a functional organelle, which requires over 40 proteins in model bacteria. The widespread distribution of flagellar genes across bacterial phyla further suggests that the last bacterial common ancestor (LBCA) already possessed a complete flagellum, though its precise composition has remained unresolved. Using a comprehensive bioinformatics framework, we reassessed flagellar gene distribution across the bacterial tree of life. Sensitive homology searches, phylogenetic filtering, and co-occurrence analyses revealed 46+2 genes consistently present in both Gracilicutes and Terrabacteria, supporting their status as ancestral components. This expanded core demonstrates that the LBCA carried a fully functional flagellum comparable to those of modern species providing new insight into the evolution of one of biologys most intricate molecular machines.
Keywords: Flagella, Evolution, Bacteria