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==Crystal structure of AbHpaI-Zn-(4S)-KDGlu complex, Class II aldolase, HpaI from Acinetobacter baumannii== | ==Crystal structure of AbHpaI-Zn-(4S)-KDGlu complex, Class II aldolase, HpaI from Acinetobacter baumannii== | ||
<StructureSection load='7etd' size='340' side='right'caption='[[7etd]]' scene=''> | <StructureSection load='7etd' size='340' side='right'caption='[[7etd]], [[Resolution|resolution]] 1.90Å' 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=7ETD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ETD FirstGlance]. <br> | <table><tr><td colspan='2'>[[7etd]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7ETD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7ETD 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=7etd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7etd OCA], [https://pdbe.org/7etd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7etd RCSB], [https://www.ebi.ac.uk/pdbsum/7etd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7etd ProSAT]</span></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=KDG:2-KETO-3-DEOXYGLUCONATE'>KDG</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr> | ||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/4-hydroxy-2-oxoheptanedioate_aldolase 4-hydroxy-2-oxoheptanedioate aldolase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.2.52 4.1.2.52] </span></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=7etd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7etd OCA], [https://pdbe.org/7etd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7etd RCSB], [https://www.ebi.ac.uk/pdbsum/7etd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7etd ProSAT]</span></td></tr> | |||
</table> | </table> | ||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Aldolases catalyze the reversible reactions of aldol condensation and cleavage and have strong potential for the synthesis of chiral compounds, widely used in pharmaceuticals. Here, we investigated a new Class II metal aldolase from the p-hydroxyphenylacetate degradation pathway in Acinetobacter baumannii, 4-hydroxy-2-keto-heptane-1,7-dioate aldolase (AbHpaI), which has various properties suitable for biocatalysis, including stereoselectivity/stereospecificity, broad aldehyde utilization, thermostability, and solvent tolerance. Notably, the use of Zn(2+) by AbHpaI as a native cofactor is distinct from other enzymes in this class. AbHpaI can also use other metal ion (M(2+)) cofactors, except Ca(2+), for catalysis. We found that Zn(2+) yielded the highest enzyme complex thermostability (Tm of 87 degrees C) and solvent tolerance. All AbHpaI*M(2+) complexes demonstrated preferential cleavage of (4R)-2-keto-3-deoxy-D-galactonate ((4R)-KDGal) over (4S)-2-keto-3-deoxy-D-gluconate ((4S)-KDGlu), with AbHpaI*Zn(2+) displaying the highest R/S stereoselectivity ratio (sixfold higher than other M(2+) cofactors). For the aldol condensation reaction, AbHpaI*M(2+) only specifically forms (4R)-KDGal and not (4S)-KDGlu and preferentially catalyzes condensation rather than cleavage by approximately 40-fold. Based on 11 X-ray structures of AbHpaI complexed with M(2+) and ligands at 1.85 to 2.0 A resolution, the data clearly indicate that the M(2+) cofactors form an octahedral geometry with Glu151 and Asp177, pyruvate, and water molecules. Moreover, Arg72 in the Zn(2+)-bound form governs the stereoselectivity/stereospecificity of AbHpaI. X-ray structures also show that Ca(2+) binds at the trimer interface via interaction with Asp51. Hence, we conclude that AbHpaI*Zn(2+) is distinctive from its homologues in substrate stereospecificity, preference for aldol formation over cleavage, and protein robustness, and is attractive for biocatalytic applications. | |||
Catalytic and structural insights into a stereospecific and thermostable Class II aldolase HpaI from Acinetobacter baumannii.,Watthaisong P, Binlaeh A, Jaruwat A, Lawan N, Tantipisit J, Jaroensuk J, Chuaboon L, Phonbuppha J, Tinikul R, Chaiyen P, Chitnumsub P, Maenpuen S J Biol Chem. 2021 Oct 5;297(5):101280. doi: 10.1016/j.jbc.2021.101280. PMID:34624314<ref>PMID:34624314</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 7etd" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
[[Category: 4-hydroxy-2-oxoheptanedioate aldolase]] | |||
[[Category: Large Structures]] | [[Category: Large Structures]] | ||
[[Category: Binlaeh A]] | [[Category: Binlaeh, A]] | ||
[[Category: Chaiyen P]] | [[Category: Chaiyen, P]] | ||
[[Category: Chitnumsub P]] | [[Category: Chitnumsub, P]] | ||
[[Category: Jaruwat A]] | [[Category: Jaruwat, A]] | ||
[[Category: Maenpuen S]] | [[Category: Maenpuen, S]] | ||
[[Category: Watthaisong P]] | [[Category: Watthaisong, P]] | ||
[[Category: Aldehyde lyase]] | |||
[[Category: Lyase]] | |||
[[Category: Tim barrel]] | |||
Revision as of 13:56, 16 February 2022
Crystal structure of AbHpaI-Zn-(4S)-KDGlu complex, Class II aldolase, HpaI from Acinetobacter baumanniiCrystal structure of AbHpaI-Zn-(4S)-KDGlu complex, Class II aldolase, HpaI from Acinetobacter baumannii
Structural highlights
Publication Abstract from PubMedAldolases catalyze the reversible reactions of aldol condensation and cleavage and have strong potential for the synthesis of chiral compounds, widely used in pharmaceuticals. Here, we investigated a new Class II metal aldolase from the p-hydroxyphenylacetate degradation pathway in Acinetobacter baumannii, 4-hydroxy-2-keto-heptane-1,7-dioate aldolase (AbHpaI), which has various properties suitable for biocatalysis, including stereoselectivity/stereospecificity, broad aldehyde utilization, thermostability, and solvent tolerance. Notably, the use of Zn(2+) by AbHpaI as a native cofactor is distinct from other enzymes in this class. AbHpaI can also use other metal ion (M(2+)) cofactors, except Ca(2+), for catalysis. We found that Zn(2+) yielded the highest enzyme complex thermostability (Tm of 87 degrees C) and solvent tolerance. All AbHpaI*M(2+) complexes demonstrated preferential cleavage of (4R)-2-keto-3-deoxy-D-galactonate ((4R)-KDGal) over (4S)-2-keto-3-deoxy-D-gluconate ((4S)-KDGlu), with AbHpaI*Zn(2+) displaying the highest R/S stereoselectivity ratio (sixfold higher than other M(2+) cofactors). For the aldol condensation reaction, AbHpaI*M(2+) only specifically forms (4R)-KDGal and not (4S)-KDGlu and preferentially catalyzes condensation rather than cleavage by approximately 40-fold. Based on 11 X-ray structures of AbHpaI complexed with M(2+) and ligands at 1.85 to 2.0 A resolution, the data clearly indicate that the M(2+) cofactors form an octahedral geometry with Glu151 and Asp177, pyruvate, and water molecules. Moreover, Arg72 in the Zn(2+)-bound form governs the stereoselectivity/stereospecificity of AbHpaI. X-ray structures also show that Ca(2+) binds at the trimer interface via interaction with Asp51. Hence, we conclude that AbHpaI*Zn(2+) is distinctive from its homologues in substrate stereospecificity, preference for aldol formation over cleavage, and protein robustness, and is attractive for biocatalytic applications. Catalytic and structural insights into a stereospecific and thermostable Class II aldolase HpaI from Acinetobacter baumannii.,Watthaisong P, Binlaeh A, Jaruwat A, Lawan N, Tantipisit J, Jaroensuk J, Chuaboon L, Phonbuppha J, Tinikul R, Chaiyen P, Chitnumsub P, Maenpuen S J Biol Chem. 2021 Oct 5;297(5):101280. doi: 10.1016/j.jbc.2021.101280. PMID:34624314[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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