Several arrangements of gamma carbonic anhydrases in Eukarya

CAINZOS MAXIMILIANO; PAGNUSSAT, GABRIELA CAROLINA; MARCHETTI, FERNANDA; EDUARDO JULIAN ZABALETA; DÍAZ, MALENA

Virtual

Congreso; LVI reunión anual SAIB; 2020

SAIB

Complex I is the main entrance of electrons into the mitochondrial oxidative phosphorylation system (OXPHOS). This respiratory chain shows different architectures through kingdoms. The eukaryotic gamma carbonic anhydrases (γCAs) are a family of metalloenzymes present in mitochondria as subunits of complex I in diverse organisms such as plants, amoeba, euglena and recently diatoms, now considered ancestral subunits. However, they are absent in animals and fungi (Opisthokonta). Particularly, the proteins have been found to be present as trimers forming a special domain within complex I named CA domain only in plants and euglena, while in amoeba and diatoms is yet to be determined. By extensive analysis of the databases of Eukarya, we found gamma CA coding sequences in the majority of kingdoms divided in two groups: γCA and γCA-like (γCAL) subunits, resembling the original groups found in A. thaliana. Based on structural considerations, we propose several different arrangements showing at least one conserved active site in the trimers of the vast majority of representative organisms.