PT - JOURNAL ARTICLE AU - Vasilis J. Promponas AU - Katerina R. Katsani AU - Benjamin J. Blencowe AU - Christos A. Ouzounis TI - Sequence evidence for common ancestry of eukaryotic endomembrane coatomers AID - 10.1101/020990 DP - 2015 Jan 01 TA - bioRxiv PG - 020990 4099 - http://biorxiv.org/content/early/2015/06/16/020990.short 4100 - http://biorxiv.org/content/early/2015/06/16/020990.full AB - Eukaryotic cells are defined by compartments through which the trafficking of macromolecules is mediated by large complexes, such as the nuclear pore, transport vesicles and intraflagellar transport. The assembly and maintenance of these complexes is facilitated by endomembrane coatomers, long suspected to be divergently related on the basis of structural and more recently phylogenomic analysis. By performing supervised walks in sequence space across coatomer superfamilies, we uncover subtle sequence patterns that have remained elusive to date, ultimately unifying eukaryotic coatomers by divergent evolution. The conserved residues shared by 3,502 endomembrane coatomer components are mapped onto the solenoid superhelix of nucleoporin and COPII protein structures, thus determining the invariant elements of coatomer architecture. This ancient structural motif can be considered as a universal signature connecting eukaryotic coatomers involved in multiple cellular processes across cell physiology and human disease.