Gamma carbonic anhydrases are subunits of the mitochondrial complex I of diatoms

CAINZOS, MAXIMILIANO; MARCHETTI, FERNANDA; POPOVICH, CECILIA; LEONARDI, PATRICIA; PAGNUSSAT, GABRIELA; ZABALETA, EDUARDO

MOLECULAR MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2021 vol. 116 p. 109 - 125

0950-382X

Diatoms are unicellular organisms containing red algal-derived plastids that probably originated as result of serial endosymbioses between an ancestral heterotrophic organism and a red alga or cryptophyte algae from which has only the chloroplast left. Diatom mitochondria are thus believed to derive from the exosymbiont. Unlike animals and fungi, diatoms seem to contain ancestral respiratory chains. In support of this, genes encoding gamma type carbonic anhydrases whose products were shown to be intrinsic complex I subunits in plants, Euglena and Achantamoeba were found in diatoms, a representative of Stramenopiles. In this work, we experimentally show that mitochondrial complex I in diatoms is a large complex containing gamma type carbonic anhydrase subunits, supporting an ancestral origin. By using a bioinformatic approach, a complex I integrated CA domain with heterotrimeric subunit composition is proposed.