View source for 8srt


==Crystal structure of the O-acetyl-L-serine sulfhydrylase A (CysK) holoenzyme from Staphylococcus aureus NCTC 8325==
<StructureSection load='8srt' size='340' side='right'caption='[[8srt]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[8srt]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Staphylococcus_aureus_subsp._aureus_NCTC_8325 Staphylococcus aureus subsp. aureus NCTC 8325]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8SRT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8SRT 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]] 1.9&#8491;</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></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=8srt FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8srt OCA], [https://pdbe.org/8srt PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8srt RCSB], [https://www.ebi.ac.uk/pdbsum/8srt PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8srt ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q2G0Q8_STAA8 Q2G0Q8_STAA8] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The pathway of bacterial cysteine biosynthesis is gaining traction for the development of antibiotic adjuvants. Bacterial cysteine biosynthesis is generally facilitated by two enzymes possessing O-acetyl-l-serine sulfhydrylases (OASS), CysK and CysM. In Staphylococcus aureus, there exists a single OASS homologue, SaCysK. Knockout of SaCysK was found to increase sensitivity to oxidative stress, making it a relevant target for inhibitor development. SaCysK also forms two functional complexes via interaction with the preceding enzyme in the pathway serine acetyltransferase (CysE) or the transcriptional regulator of cysteine metabolism (CymR). These interactions occur through insertion of a C-terminal peptide of CysE or CymR into the active site of SaCysK, inhibiting OASS activity, and therefore represent an excellent starting point for developing SaCysK inhibitors. Here, we detail the characterization of CysE and CymR-derived C-terminal peptides as inhibitors of SaCysK. Using a combination of X-ray crystallography, surface plasmon resonance, and enzyme inhibition assays, it was determined that the CymR-derived decapeptide forms extensive interactions with SaCysK and acts as a potent inhibitor (K(D) = 25 nM; IC(50) = 180 nM), making it a promising lead for the development of SaCysK inhibitors. To understand the determinants of this high-affinity interaction, the structure-activity relationships of 16 rationally designed peptides were also investigated. This identified that the C-terminal pentapeptide of CymR facilitates the high-affinity interaction with SaCysK and that subtle structural modification of the pentapeptide is possible without impacting potency. Ultimately, this work identified CymR pentapeptides as a promising scaffold for the development of antibiotic adjuvants targeting SaCysK.

Identification of Cysteine Metabolism Regulator (CymR)-Derived Pentapeptides as Nanomolar Inhibitors of Staphylococcus aureus O-Acetyl-l-serine Sulfhydrylase (CysK).,Pederick JL, Vandborg BC, George A, Bovermann H, Boyd JM, Freundlich JS, Bruning JB ACS Infect Dis. 2025 Jan 10;11(1):238-248. doi: 10.1021/acsinfecdis.4c00832. Epub , 2024 Dec 20. PMID:39705018<ref>PMID:39705018</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 8srt" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Staphylococcus aureus subsp. aureus NCTC 8325]]
[[Category: Bruning JB]]
[[Category: Pederick JL]]
[[Category: Vandborg BC]]