7k34: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 1: | Line 1: | ||
==Crystal structure of L-threonine transaldolase from Pseudomonas fluorescens in internal aldimine state== | ==Crystal structure of L-threonine transaldolase from Pseudomonas fluorescens in internal aldimine state== | ||
<StructureSection load='7k34' size='340' side='right'caption='[[7k34]]' scene=''> | <StructureSection load='7k34' size='340' side='right'caption='[[7k34]], [[Resolution|resolution]] 1.66Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7K34 OCA]. For a <b>guided tour on the structure components</b> use [ | <table><tr><td colspan='2'>[[7k34]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_fluorescens Pseudomonas fluorescens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7K34 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7K34 FirstGlance]. <br> | ||
</td></tr><tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.66Å</td></tr> | ||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=LLP:(2S)-2-AMINO-6-[[3-HYDROXY-2-METHYL-5-(PHOSPHONOOXYMETHYL)PYRIDIN-4-YL]METHYLIDENEAMINO]HEXANOIC+ACID'>LLP</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=7k34 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7k34 OCA], [https://pdbe.org/7k34 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7k34 RCSB], [https://www.ebi.ac.uk/pdbsum/7k34 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7k34 ProSAT]</span></td></tr> | |||
</table> | </table> | ||
== Function == | |||
[https://www.uniprot.org/uniprot/A0A1X9LWZ7_PSEFL A0A1X9LWZ7_PSEFL] | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
l-Threonine transaldolases (lTTAs) are a poorly characterized class of pyridoxal-5'-phosphate (PLP) dependent enzymes responsible for the biosynthesis of diverse beta-hydroxy amino acids. Here, we study the catalytic mechanism of ObiH, an lTTA essential for biosynthesis of the beta-lactone natural product obafluorin. Heterologously expressed ObiH purifies as a mixture of chemical states including a catalytically inactive form of the PLP cofactor. Photoexcitation of ObiH promotes the conversion of the inactive state of the enzyme to the active form. UV-vis spectroscopic analysis reveals that ObiH catalyzes the retro-aldol cleavage of l-threonine to form a remarkably persistent glycyl quinonoid intermediate, with a half-life of approximately 3 h. Protonation of this intermediate is kinetically disfavored, enabling on-cycle reactivity with aldehydes to form beta-hydroxy amino acids. We demonstrate the synthetic potential of ObiH via the single step synthesis of (2S,3R)-beta-hydroxyleucine. To further understand the structural features underpinning this desirable reactivity, we determined the crystal structure of ObiH bound to PLP as the Schiff's base at 1.66 A resolution. This high-resolution model revealed a unique active site configuration wherein the evolutionarily conserved Asp that traditionally H-bonds to the cofactor is swapped for a neighboring Glu. Molecular dynamics simulations combined with mutagenesis studies indicate that a structural rearrangement is associated with l-threonine entry into the catalytic cycle. Together, these data explain the basis for the unique reactivity of lTTA enzymes and provide a foundation for future engineering and mechanistic analysis. | |||
l-Threonine Transaldolase Activity Is Enabled by a Persistent Catalytic Intermediate.,Kumar P, Meza A, Ellis JM, Carlson GA, Bingman CA, Buller AR ACS Chem Biol. 2020 Dec 18. doi: 10.1021/acschembio.0c00753. PMID:33337128<ref>PMID:33337128</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 7k34" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Aldolase 3D structures|Aldolase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: Large Structures]] | [[Category: Large Structures]] | ||
[[Category: Pseudomonas fluorescens]] | |||
[[Category: Bingman CA]] | [[Category: Bingman CA]] | ||
[[Category: Buller AR]] | [[Category: Buller AR]] | ||
[[Category: Kumar P]] | [[Category: Kumar P]] | ||
Latest revision as of 15:16, 18 October 2023
Crystal structure of L-threonine transaldolase from Pseudomonas fluorescens in internal aldimine state
| ||||||||||||
