ADP-glucose Pyrophosphorylase from Gram Positive Bacteria

C.M. FIGUEROA; A.M. DEMONTE; D. ARIAS; F. FERRONI; D. GONZÁLEZ; S. GUERRERO; A.A. IGLESIAS; M.A. BALLICORA; J. PREISS

Iguazú, Misiones, Argentina

Congreso; XL Reunión de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB); 2004

SAIB

BIOCELL 28 (Suppl.), 2004 75ES-P14.ADP-GLUCOSE PYROPHOSPHORYLASE FROM GRAM POSITIVE BACTERIAFigueroa CM, Demonte AM, Arias D, Ferroni F, González D, Guerrero S, Iglesias AA, Ballicora MA*, Preiss J*.Lab. Enzimología Molecular, Fac. Bioquímica y Cs. Biológicas, UNL, Paraje "El Pozo", S3000ZAA, Santa Fé, Argentina; and *Dept. Biochemistry & Mol. Biol., Michigan State University, E. Lansing, MI 48824, USA. E-mail: carfigue@fbcb.unl.edu.arGlycogen synthesis in bacteria takes place by the pathway utilizing ADP-Glc as the glucosyl donor, being the reaction catalyzed by the enzyme ADP-Glc pyrophosphorylase (ADP-Glc PPase) the regulatory step. ADP-Glc PPase from Gram negative bacteria has been extensively studied, mainly from Escherichia coli and Agrobacterium tumefaciens. In these, the enzyme was characterized as a homotetramer allosterically regulated by key metabolites of the main pathway for carbon utilization in the respective organism. Conversely, studies on ADP-Glc PPases from Gram positive bacteria are scarce. Between the latter, and after analysis of genome projects, two types could be distinguished: those from the firmicutes (low G+C) group that contain two different genes (glgC and glgD) coding for ADP-Glc PPase; and those from the high G+C group having only the glgC gene, as occurs in all other bacteria. We performed the molecular cloning of the genes coding for ADP-Glc PPase from different Gram positive bacteria: Mycobacterium tuberculosis and Streptomyces coelicolor (high G+C); and from Streptococcus mutans (low G+C). The respective genes were expressed and the recombinant proteins purified and characterized. Results show that the ADP-Glc PPases with the different structures exhibit dissimilar regulatory properties that could be associated with the distinctive metabolic pathwaysoccurring in each microbial organism