8d27: Difference between revisions

<table><tr><td colspan='2'>[[8d27]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8D27 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8D27 FirstGlance]. <br>

</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=8d27 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8d27 OCA], [https://pdbe.org/8d27 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8d27 RCSB], [https://www.ebi.ac.uk/pdbsum/8d27 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8d27 ProSAT]</span></td></tr>

== Publication Abstract from PubMed ==

A number of species within the Fusobacteriaceae family of Gram-negative bacteria uniquely encode for an ornithine decarboxylase/arginase (ODA) that ostensibly channels l-ornithine generated by hydrolysis of l-arginine to putrescine formation. However, two aspartate residues required for coordination to a catalytically obligatory manganese cluster of arginases are substituted for a serine and an asparagine. Curiously, these natural substitutions occur only in a clade of Fusobacterium species that inhabit the oral cavity. Herein, we expressed and isolated full-length ODA from the opportunistic oral pathogen Fusobacterium nucleatum along with the individual arginase and ornithine decarboxylase components. The crystal structure of the arginase domain reveals that it adopts the classical alpha/beta arginase-fold, but metal ions are absent in the active site. As expected, the ureohydrolase activity with l-arginine was not detected for wild-type ODA or the isolated arginase domain. However, engineering of the complete metal coordination environment through site-directed mutagenesis restored Mn(2+) binding capacity and arginase activity, although the catalytic efficiency for l-arginine was low (60-100 M(-1) s(-1)). Full-length ODA and the isolated ODC component were able to decarboxylate both l-ornithine and l-arginine to form putrescine and agmatine, respectively, but kcat/KM of l-ornithine was approximately 20-fold higher compared to l-arginine. We discuss environmental conditions that may have led to the natural selection of an inactive arginase in the oral associated species of Fusobacterium.

 

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== References ==

[[Category: Chan, A C]]

[[Category: Kolesnikov, M]]

[[Category: Murphy, M E]]

[[Category: Ornithine decarboxylase/arginase]]