View source for 6ytj


==Magnesium chelatase H subunit (ChlH) E625K variant from Synechocystis sp.PCC6803==
<StructureSection load='6ytj' size='340' side='right'caption='[[6ytj]], [[Resolution|resolution]] 2.79&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6ytj]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Synechocystis_sp._PCC_6803 Synechocystis sp. PCC 6803]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6YTJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6YTJ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.79&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=6ytj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6ytj OCA], [https://pdbe.org/6ytj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6ytj RCSB], [https://www.ebi.ac.uk/pdbsum/6ytj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6ytj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/P73020_SYNY3 P73020_SYNY3] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The insertion of magnesium into protoporphyrin initiates the biosynthesis of chlorophyll, the pigment that underpins photosynthesis. This reaction, catalysed by the magnesium chelatase complex, couples ATP hydrolysis by a ChlID motor complex to chelation within the ChlH subunit. We probed the structure and catalytic function of ChlH using a combination of X-ray crystallography, computational modelling, mutagenesis and enzymology. Two linked domains of ChlH in an initially open conformation of ChlH bind protoporphyrin IX, and the rearrangement of several loops envelops this substrate, forming an active site cavity. This induced fit brings an essential glutamate (E660), proposed to be the key catalytic residue for magnesium insertion, into proximity with the porphyrin. A buried solvent channel adjacent to E660 connects the exterior bulk solvent to the active site, forming a possible conduit for the delivery of magnesium or abstraction of protons.

The active site of magnesium chelatase.,Adams NBP, Bisson C, Brindley AA, Farmer DA, Davison PA, Reid JD, Hunter CN Nat Plants. 2020 Nov 30. pii: 10.1038/s41477-020-00806-9. doi:, 10.1038/s41477-020-00806-9. PMID:33257858<ref>PMID:33257858</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6ytj" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Synechocystis sp. PCC 6803]]
[[Category: Bisson C]]
[[Category: Hunter CN]]