Novel Monofunctional Histidinol Phosphatase of the DDDD Superfamily of Phosphohydrolases

Abstract

Histidinol Phosphatase (HPase) is a committed enzyme in the eighth step of histidine biosynthesis pathway. Genes for all enzymes of the pathway except HPase are found in a genome of the hyperthermophilic archaeon Thermococcus onnurineus NA1. In this study, a gene (TON_0887) to encode a putative HAD superfamily hydrolase was identified as the best candidate for the missing HPase gene by the analysis of his gene cluster. TON_0887 displayed three or four order of magnitude preference for histidinol phosphate to AMP, fructose 6-phosphate or phosphoserine. Based on the genome analysis of Thermococcus kodakaraensis and Phyrococcus furiosus, two orthologues of TON_0887 are anticipated to represent the missing HPases. Our work provides the first assessment of a monofunctional HPase belong to the DDDD superfamily of phosphohydrolases.