View source for 4mck


==Crystal structure of Family GH19, Class IV chitinase from Zea mays==
<StructureSection load='4mck' size='340' side='right'caption='[[4mck]], [[Resolution|resolution]] 1.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4mck]] is a 1 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=4MCK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4MCK 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]] 1.5&#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=4mck FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mck OCA], [https://pdbe.org/4mck PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4mck RCSB], [https://www.ebi.ac.uk/pdbsum/4mck PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4mck ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CHIA_MAIZE CHIA_MAIZE] Defense against chitin-containing fungal pathogens (PubMed:1551872, Ref.6). Hydrolyzes glycol chitin and tetra-N-acetylchitotetraose in vitro (PubMed:28328103). Its action is countered by fungal polyglycine hydrolases and fungalysin, that cleave the chitin-binding domain from the protein (PubMed:21453431, PubMed:24627966, PubMed:25966977, PubMed:35240278, PubMed:36762862, Ref.6).<ref>PMID:1551872</ref> <ref>PMID:21453431</ref> <ref>PMID:24627966</ref> <ref>PMID:25966977</ref> <ref>PMID:28328103</ref> <ref>PMID:35240278</ref> <ref>PMID:36762862</ref> <ref>PMID:24616181</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Maize ChitA chitinase is composed of a small, hevein-like domain attached to a carboxy-terminal chitinase domain. During fungal ear rot, the hevein-like domain is cleaved by secreted fungal proteases to produce truncated forms of ChitA. Here, we report a structural and biochemical characterization of truncated ChitA (ChitA DeltaN), which lacks the hevein-like domain. ChitA DeltaN and a mutant form (ChitA DeltaN-EQ) were expressed and purified; enzyme assays showed that ChitA DeltaN activity was comparable to the full-length enzyme. Mutation of Glu62 to Gln (ChitA DeltaN-EQ) abolished chitinase activity without disrupting substrate binding, demonstrating that Glu62 is directly involved in catalysis. A crystal structure of ChitA DeltaN-EQ provided strong support for key roles for Glu62, Arg177, and Glu165 in hydrolysis, and for Ser103 and Tyr106 in substrate binding. These findings demonstrate that the hevein-like domain is not needed for enzyme activity. Moreover, comparison of the crystal structure of this plant class IV chitinase with structures from larger class I and II enzymes suggest that class IV chitinases have evolved to accommodate shorter substrates.

Crystallographic structure of ChitA, a glycoside hydrolase family 19, plant class IV chitinase from Zea mays.,Chaudet MM, Naumann TA, Price NP, Rose DR Protein Sci. 2014 Feb 6. doi: 10.1002/pro.2437. PMID:24616181<ref>PMID:24616181</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4mck" style="background-color:#fffaf0;"></div>

==See Also==
*[[Chitinase 3D structures|Chitinase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Zea mays]]
[[Category: Chaudet MM]]
[[Category: Rose DR]]