CAZyme Annotation of Five Parasitic Trichomonads Reveals a Conserved Repertoire of Host Glycan Targeting Proteins

Abstract

Deciphering the functional potential of the unusually large and repetitive genomes of trichomonads has remained challenging since the first Trichomonas vaginalis genome assembly in 2007. These genomes are characterised by extensive gene duplication, widespread lateral gene transfer from prokaryotes, and numerous hypothetical proteins. Here, we systematically re-annotated five parasitic trichomonad genomes using the CAZy annotation pipeline, identifying 1,406 CAZyme-encoding genes (which encompass all four core CAZyme classes and carbohydrate-binding modules (CBMs)) - including 516 genes previously annotated as encoding hypothetical proteins - and generating predictions of CAZy genes originating from potential lateral gene transfer, encoding candidate secreted proteins, and their candidate metabolic pathway involvement. Comparative analyses revealed a conserved, highly duplicated repertoire of candidate mucin O-glycan-targeting CAZymes across all five species, alongside broad conservation of a candidate antibacterial CAZyme toolkit. Together, these findings substantially enrich functional annotation of these genomes and highlight in particular CAZymes and CBMs as promising targets for the future characterisation of the molecular and cellular basis of parasite-host and parasite-microbiota interactions underlying mucosal disease and dysbiosis associated with trichomonads.