<p>This group of sequences belong to the IB subfamily of the haloacid dehalogenase (HAD) superfamily of aspartate-nucleophile hydrolases. The sequences are all from archaeal species. The phylogenetically closest group of sequences to these are phosphoserine phosphatases. As there are no known archaeal phosphoserine phosphatases, it seems likely that this group of sequences represent the archaeal branch of PSPase.</p> HAD-superfamily hydrolase, subfamily IB, PSPase-like, archaeal