Abstract
EstN2 is a novel α/β-hydrolase originating from the ammonia-oxidizing thaumarchaeon Candidatus Nitrososphaera gargensis. The genome of the organism was sequenced and genes conferring putative lipolytic activity were amplified and cloned into Escherichia coli as a heterologous host. Through function-based screening, esterase and lipase activity was detected. A recombinant enzyme designated EstN2 was successfully expressed, purified and crystallized. The crystals belonged to space group I2, with one molecule per asymmetric unit, and diffracted X-rays to 1.5 Å resolution.