A comparison of the crystal structures of bacterial l-asparaginases

Abstract

Publisher Summary This chapter discusses a systematic comparison of the enzymes, such as L-asparaginase, from Escherichia coli with bound aspartate (EcA), L-asparaginase from Erwinia chrysanthemi with bound sulphate or with bound L-aspartate (ErA), L-glutaminase-L-asparaginase from Acinetobacter glutaminasificans (AGA), and L-glutaminase-L-asparaginase from Pseudomonas (PGA) in terms of their sequence, structure, and the geometry of the active site. Type I or type II bacterial L-asparaginase catalyzes the hydrolysis of L-asparagine to L-aspartate, with the release of ammonia. The type II bacterial L-asparaginases have a unique and characteristic topological fold. Type II L-asparaginases from Bacillus licheniformis and the yeast enzyme from Saccharomyces cerevisiae as well as the type I asparaginases from E. coli, Bacillus subtilis, and cytosolic Saccharomyces cerevisiae bear sequence resemblance with EcA, ErA, AGA, and PGA enzymes. In contrast, plant asparaginases do not have sequence similarity with the bacterial enzymes.