View source for 5ou5


==Crystal structure of maize chloroplastic photosynthetic NADP(+)-dependent malic enzyme==
<StructureSection load='5ou5' size='340' side='right'caption='[[5ou5]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5ou5]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Zea_mays Zea mays]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5OU5 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5OU5 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]] 2.2&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=K:POTASSIUM+ION'>K</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene></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=5ou5 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5ou5 OCA], [https://pdbe.org/5ou5 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5ou5 RCSB], [https://www.ebi.ac.uk/pdbsum/5ou5 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5ou5 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/MAOC_MAIZE MAOC_MAIZE] The chloroplastic ME isoform decarboxylates malate shuttled from neighboring mesophyll cells. The CO(2) released is then refixed by ribulose-bisphosphate carboxylase. This pathway eliminates the photorespiratory loss of CO(2) that occurs in most plants.<ref>PMID:31235877</ref> 
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== Publication Abstract from PubMed ==
In C4 grasses of agronomical interest, malate shuttled into the bundle sheath cells is decarboxylated mainly by nicotinamide adenine dinucleotide phosphate (NADP)-malic enzyme (C4-NADP-ME). The activity of C4-NADP-ME was optimized by natural selection to efficiently deliver CO2 to Rubisco. During its evolution from a plastidic non-photosynthetic NADP-ME, C4-NADP-ME acquired increased catalytic efficiency, tetrameric structure and pH-dependent inhibition by its substrate malate. Here, we identified specific amino acids important for these C4 adaptions based on strict differential conservation of amino acids, combined with solving the crystal structures of maize and sorghum C4-NADP-ME. Site-directed mutagenesis and structural analyses show that Q503, L544 and E339 are involved in catalytic efficiency; E339 confers pH-dependent regulation by malate, F140 is critical for the stabilization of the oligomeric structure and the N-terminal region is involved in tetramerization. Together, the identified molecular adaptations form the basis for the efficient catalysis and regulation of one of the central biochemical steps in C4 metabolism.

Molecular adaptations of NADP-malic enzyme for its function in C4 photosynthesis in grasses.,Alvarez CE, Bovdilova A, Hoppner A, Wolff CC, Saigo M, Trajtenberg F, Zhang T, Buschiazzo A, Nagel-Steger L, Drincovich MF, Lercher MJ, Maurino VG Nat Plants. 2019 Jul;5(7):755-765. doi: 10.1038/s41477-019-0451-7. Epub 2019 Jun , 24. PMID:31235877<ref>PMID:31235877</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 5ou5" style="background-color:#fffaf0;"></div>

==See Also==
*[[NADP-dependent malic enzyme|NADP-dependent malic enzyme]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Zea mays]]
[[Category: Bovdilova A]]
[[Category: Hoeppner A]]
[[Category: Maurino VG]]