GAMMA CARBONIC ANHIDRASE LIKE PROTEINS ARE PRESENT IN MITOCHONDRIAL COMPLEX I OF THE DIATOM PHAEODACTYLUM TRICORNUTUM

PAGNUSSAT G; CAINZOS, MAXIMILIANO; EDUARDO JULIAN ZABALETA; MARCHETTI, MARIA FERNANDA

Salta

Congreso; LV Reunión Anual de SAIB; 2019

Diatoms are a major group of algae responsible for the 20% of CO2 global fixation. P.tricornutum is commonly used in molecular biology as a model organism for understanding the biology of diatoms. Diatoms are the result of a symbiosis between an ancestral heterotrophic organism (called the exosymbiont) with a red algae (known as the endosymbiont) from which has only the chloroplast left. Diatom mitochondria are then believed to derive from the exosymbiont, the ?animal part?. However, these organisms seem to contain ancestral OXPHOS different from Opisthokonta (animals and fungi). In support of this, genes encoding gamma type carbonic anhydrases that were shown to be intrinsic complex I subunits in plants and in amoeba but not in animals and fungi were found in all other eukaryote lineages. Here, we show that diatom complex I is a large complex containing gamma type carbonic anhydrases subunits, supporting an ancestral origin.