Rv2577 of Mycobacterium tuberculosis is a virulence factor with dual phosphatase and phosphodiesterase functions

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Abstract

Tuberculosis, a lung disease caused by , is one of the ten leading causes of death worldwide affecting mainly developing countries. can persist and survive inside infected cells through modulation of host antibacterial attack, i.e., by avoiding the maturation of phagosome containing mycobacteria to more acidic endosomal compartment. In addition, bacterial phosphatases play a central role in the interplay between host cells and . In this study, we characterized the Rv2577 of as a potential alkaline phosphatase/phosphodiesterase enzyme. By an kinetic assay, we demonstrated that purified Rv2577 expressed in displays both enzyme activities, as evidenced by using the artificial substrates NPP and bis-(NPP). In addition, a three-dimensional model of Rv2577 allowed us to define the catalytic amino acid residues of the active site, which were confirmed by site-directed mutagenesis and enzyme activity analysis, being characteristic of a member of the metallophosphatase superfamily. Finally, a mutation introduced in Rv2577 reduced the replication of in mouse organs and impaired the arrest of phagosomes containing mycobacteria in early endosomes; which indicates Rv2577 plays a role in virulence.