Structure and mechanism of the 2′,3′ phosphatase component of the bacterial Pnkp-Hen1 RNA repair system Journal Article

   

Authors:	Wang, L. K.; Smith, P.; Shuman, S.
Article Title:	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 Mn2+-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 Mn2+ 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 Mn2+ in an octahedral coordination complex with Asp187, His189, Asp233, two citrate oxygens and a water. The citrate fills the binding site for the scissile phosphate, wherein it is coordinated by Arg237, Asn263 and His264. The citrate invades the site normally occupied by a second metal (engaged by Asp233, Asn263, His323 and His376), and thereby dislocates His376. A continuous tract of positive surface potential flanking the active site suggests an RNA binding site. The structure illuminates a large body of mutational data regarding the metal and substrate specificity of Clostridium thermocellum Pnkp phosphatase. © 2013 The Author(s).
Journal Title:	Nucleic Acids Research
Volume:	41
Issue:	11
ISSN:	0305-1048
Publisher:	Oxford University Press
Date Published:	2013-06-01
Start Page:	5864
End Page:	5873
Language:	English
DOI:	10.1093/nar/gkt221
PROVIDER:	scopus
PMCID:	PMC3675462
PUBMED:	23595150
DOI/URL:	http://www.scopus.com/inward/record.url?eid=2-s2.0-84878881368&partnerID=40&md5=7383543421648950ea33c30ab9cd5f54
Notes:	--- - "Export Date: 1 July 2013" - "CODEN: NARHA" - "Source: Scopus"

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