View source for 7vum


==Crystal structure of SSB complexed with que==
<StructureSection load='7vum' size='340' side='right'caption='[[7vum]], [[Resolution|resolution]] 2.32&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[7vum]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Pseudomonas_aeruginosa_PAO1 Pseudomonas aeruginosa PAO1]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=7VUM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=7VUM 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]] 2.319&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=QUE:3,5,7,3,4-PENTAHYDROXYFLAVONE'>QUE</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=7vum FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=7vum OCA], [https://pdbe.org/7vum PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=7vum RCSB], [https://www.ebi.ac.uk/pdbsum/7vum PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=7vum ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SSB_PSEAE SSB_PSEAE] Plays an important role in DNA replication, recombination and repair. Binds to ssDNA and to an array of partner proteins to recruit them to their sites of action during DNA metabolism.[HAMAP-Rule:MF_00984]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Single-stranded DNA (ssDNA)-binding protein (SSB) plays a crucial role in DNA replication, repair, and recombination as well as replication fork restarts. SSB is essential for cell survival and, thus, is an attractive target for potential antipathogen chemotherapy. Whether naturally occurring products can inhibit SSB remains unknown. In this study, the effect of the flavonols myricetin, quercetin, kaempferol, and galangin on the inhibition of Pseudomonas aeruginosa SSB (PaSSB) was investigated. Furthermore, SSB was identified as a novel quercetin-binding protein. Through an electrophoretic mobility shift analysis, myricetin could inhibit the ssDNA binding activity of PaSSB with an IC50 of 2.8 +/- 0.4 muM. The effect of quercetin, kaempferol, and galangin was insignificant. To elucidate the flavonol inhibition specificity, the crystal structure of PaSSB complexed with the non-inhibitor quercetin was solved using the molecular replacement method at a resolution of 2.3 A (PDB entry 7VUM) and compared with a structure with the inhibitor myricetin (PDB entry 5YUN). Although myricetin and quercetin bound PaSSB at a similar site, their binding poses were different. Compared with myricetin, the aromatic ring of quercetin shifted by a distance of 4.9 A and an angle of 31(o) for hydrogen bonding to the side chain of Asn108 in PaSSB. In addition, myricetin occupied and interacted with the ssDNA binding sites Lys7 and Glu80 in PaSSB whereas quercetin did not. This result might explain why myricetin could, but quercetin could not, strongly inhibit PaSSB. This molecular evidence reveals the flavonol inhibition specificity and also extends the interactomes of the natural anticancer products myricetin and quercetin to include the OB-fold protein SSB.

A Complexed Crystal Structure of a Single-Stranded DNA-Binding Protein with Quercetin and the Structural Basis of Flavonol Inhibition Specificity.,Lin ES, Luo RH, Huang CY Int J Mol Sci. 2022 Jan 6;23(2). pii: ijms23020588. doi: 10.3390/ijms23020588. PMID:35054774<ref>PMID:35054774</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 7vum" style="background-color:#fffaf0;"></div>

==See Also==
*[[Single-stranded DNA-binding protein 3D structures|Single-stranded DNA-binding protein 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Pseudomonas aeruginosa PAO1]]
[[Category: Huang CY]]
[[Category: Huang YH]]
[[Category: Lin ES]]