4dwr

<StructureSection load='4dwr' size='340' side='right' caption='[[4dwr]], [[Resolution|resolution]] 1.48&Aring;' scene=''>

<table><tr><td colspan='2'>[[4dwr]] is a 3 chain structure with sequence from [http://en.wikipedia.org/wiki/'pyrococcus_shinkaii' 'pyrococcus shinkaii']. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4DWR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4DWR FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <scene name='pdbligand=SUC:SUCROSE'>SUC</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4dwq|4dwq]]</td></tr>

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4dwr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4dwr OCA], [http://pdbe.org/4dwr PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4dwr RCSB], [http://www.ebi.ac.uk/pdbsum/4dwr PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4dwr ProSAT]</span></td></tr>

[[http://www.uniprot.org/uniprot/RTCB_PYRHO RTCB_PYRHO]] tRNA-splicing ligase that acts by directly joining spliced tRNA halves to mature-sized tRNAs by incorporating the precursor-derived splice junction phosphate into the mature tRNA as a canonical 3',5'-phosphodiester. May act as a RNA ligase with broad substrate specificity, and may function toward other RNAs (By similarity).

The RtcB protein has recently been identified as a 3'-phosphate RNA ligase that directly joins an RNA strand ending with a 2',3'-cyclic phosphate to the 5'-hydroxyl group of another RNA strand in a GTP/Mn(2+)-dependent reaction. Here, we report two crystal structures of Pyrococcus horikoshii RNA-splicing ligase RtcB in complex with Mn(2+) alone (RtcB/ Mn(2+)) and together with a covalently bound GMP (RtcB-GMP/Mn(2+)). The RtcB/ Mn(2+) structure (at 1.6 A resolution) shows two Mn(2+) ions at the active site, and an array of sulfate ions nearby that indicate the binding sites of the RNA phosphate backbone. The structure of the RtcB-GMP/Mn(2+) complex (at 2.3 A resolution) reveals the detailed geometry of guanylylation of histidine 404. The critical roles of the key residues involved in the binding of the two Mn(2+) ions, the four sulfates, and GMP are validated in extensive mutagenesis and biochemical experiments, which also provide a thorough characterization for the three steps of the RtcB ligation pathway: (i) guanylylation of the enzyme, (ii) guanylyl-transfer to the RNA substrate, and (iii) overall ligation. These results demonstrate that the enzyme's substrate-induced GTP binding site and the putative reactive RNA ends are in the vicinity of the binuclear Mn(2+) active center, which provides detailed insight into how the enzyme-bound GMP is tansferred to the 3'-phosphate of the RNA substrate for activation and subsequent nucleophilic attack by the 5'-hydroxyl of the second RNA substrate, resulting in the ligated product and release of GMP.

 

<div class="pdbe-citations 4dwr" style="background-color:#fffaf0;"></div>

== References ==

[[Category: Pyrococcus shinkaii]]

[[Category: Englert, M]]

[[Category: Soll, D]]

[[Category: Wang, J]]

[[Category: Xia, S]]

[[Category: Rtcb]]