Structure and mechanism of the 2',3' phosphatase component of the bacterial Pnkp-Hen1 RNA repair system.

ABSTRACT: Pnkp is the end-healing and end-sealing component of an RNA repair system present in diverse bacteria from many phyla. Pnkp is composed of three catalytic modules: an N-terminal polynucleotide 5' kinase, a central 2',3' phosphatase and a C-terminal ligase. The phosphatase module is a Mn(2+)-dependent phosphodiesterase-monoesterase that dephosphorylates 2',3'-cyclic phosphate RNA ends. Here we report the crystal structure of the phosphatase domain of Clostridium thermocellum Pnkp with Mn(2+) and citrate in the active site. The protein consists of a core binuclear metallo-phosphoesterase fold (exemplified by bacteriophage λ phosphatase) embellished by distinctive secondary structure elements. The active site contains a single Mn(2+) in an octahedral coordination complex with Asp187, His189,

SUBMITTER: Wang LK 

PROVIDER: S-EPMC3675462 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature