Looking into the thermostable archaeal l-asparaginases

l -asparaginases catalyze the conversion of l -asparagine to aspartate. Their potential as antineoplastic drug and as a processing aid for acrylamide mitigation during food processing has created a special interest. These applications require l -asparaginases with longer half-lives and no or negligible catalytic activity against other amino acids. Hyperthermophilic archaea are promising source of such l -asparaginases. Analysis of genome sequences revealed that most of the hyperthermophilic archaea contain more than one type of l -asparaginase. Indeed, two types of l -asparaginases, a bacterial-type I and a plant-type, have been characterized from a few archaeal members. This article is an attempt to summarize the current understanding of thermophilic archaeal l -asparaginases with emphasis on structural insights and potential functional applications.