1fsi

<table><tr><td colspan='2'>[[1fsi]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FSI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1FSI FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>

[[https://www.uniprot.org/uniprot/CPD_ARATH CPD_ARATH]] Hydrolyzes ADP-ribose 1",2"-cyclic phosphate (Appr>1) that is produced during tRNA splicing into ADP-ribose 1"-phosphate (Appr-1"p). Acts also on nucleoside 2',3'-cyclic phosphates.

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== Publication Abstract from PubMed ==

The crystal structure of the cyclic phosphodiesterase (CPDase) from Arabidopsis thaliana, an enzyme involved in the tRNA splicing pathway, was determined at 2.5 A resolution. CPDase hydrolyzes ADP-ribose 1",2"-cyclic phosphate (Appr&gt;p), a product of the tRNA splicing reaction, to the monoester ADP-ribose 1"-phosphate (Appr-1"p). The 181 amino acid protein shows a novel, bilobal arrangement of two alphabeta modules. Each lobe consists of two alpha-helices on the outer side of the molecule, framing a three- or four-stranded antiparallel beta-sheet in the core of the protein. The active site is formed at the interface of the two beta-sheets in a water-filled cavity involving residues from two H-X-T/S-X motifs. This previously noticed motif participates in coordination of a sulfate ion. A solvent-exposed surface loop (residues 100-115) is very likely to play a flap-like role, opening and closing the active site. Based on the crystal structure and on recent mutagenesis studies of a homologous CPDase from Saccharomyces cerevisiae, we propose an enzymatic mechanism that employs the nucleophilic attack of a water molecule activated by one of the active site histidines.

Structure and mechanism of activity of the cyclic phosphodiesterase of Appr&gt;p, a product of the tRNA splicing reaction.,Hofmann A, Zdanov A, Genschik P, Ruvinov S, Filipowicz W, Wlodawer A EMBO J. 2000 Nov 15;19(22):6207-17. PMID:11080166<ref>PMID:11080166</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Filipowicz, W]]

[[Category: Genschik, P]]

[[Category: Hofmann, A]]

[[Category: Ruvinov, S]]

[[Category: Wlodawer, A]]

[[Category: Zdanov, A]]

[[Category: Hydrolase]]