CRDSP, a phosphoglucan phosphatase involved in starch metabolism in C. reinhardtii.

MORALES, L.; CARRILLO J.B.; DIEGO FABIAN GOMEZ CASATI; BUSI, M. V.; MARTIN, M.

Córdoba

Congreso; LII Reunión de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2016

SAIB

Phosphatases are enzymesthat remove phosphate groups from a wide variety of substrates such us proteins,glucans, nucleic acids and lipids. It has recently become clear thatdephosphorylation of glucans is essential for normal starch degradation inplants as well as glycogen metabolism in mammals. To understand theevolution of catalysis and regulation of these enzymes we decided toinvestigate their existence in unicellular green algae. C.reinharditii transcriptome BLAST searches revealed one locus encoding aprotein with high sequence similarity to A.thaliana starch excess 4 enzyme. An exhaustive in silico analysis led us to conclude that the putative protein could be a chloroplastic enzyme withsimilar structural features to its plant counterpart. Tofurther characterize this finding the cDNA was cloned to express and purify therecombinant protein in E. coli cells.We verified phosphatase activity of the recombinant enzyme in vitro as well as its ability to bind polysaccharides.