View source for 6t76


==PII-like protein CutA from Nostoc sp. PCC 7120 in apo form==
<StructureSection load='6t76' size='340' side='right'caption='[[6t76]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6t76]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Nostoc_sp._PCC_7120_=_FACHB-418 Nostoc sp. PCC 7120 = FACHB-418]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6T76 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6T76 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=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=6t76 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6t76 OCA], [https://pdbe.org/6t76 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6t76 RCSB], [https://www.ebi.ac.uk/pdbsum/6t76 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6t76 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q8YL42_NOSS1 Q8YL42_NOSS1] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The PII-like protein CutA is annotated as being involved in Cu(2+) tolerance, based on analysis of Escherichia coli mutants. However, the precise cellular function of CutA remains unclear. Our bioinformatic analysis reveals that CutA proteins are universally distributed across all domains of life. Based on sequence-based clustering, we chose representative cyanobacterial CutA proteins for physiological, biochemical and structural characterization and examined their involvement in heavy metal tolerance, by generating CutA mutants in filamentous Nostoc sp. and in unicellular Synechococcus elongatus. However, we were unable to find any involvement of cyanobacterial CutA in metal tolerance under various conditions. This prompted us to re-examine experimentally the role of CutA in protecting E. coli from Cu(2+) . Since we found no effect on copper-tolerance, we conclude that CutA plays a different role that is not involved in metal protection. We resolved high-resolution CutA structures from Nostoc and S elongatus. Similarly to its counterpart from E.coli and to canonical PII proteins, cyanobacterial CutA proteins are trimeric in solution and in crystal structure; however, no binding affinity for small signaling molecules or for Cu(2+) could be detected. The clefts between the CutA subunits, corresponding to the binding pockets of PII proteins, are formed by conserved aromatic and charged residues, suggesting a conserved binding/signaling function for CutA. In fact, we find binding of organic Bis-Tris/MES molecules in CutA crystal structures, revealing a strong tendency of these pockets to accommodate cargo. This highlights the need to search for the potential physiological ligands and for their signaling functions upon binding to CutA.

Functional and structural characterization of PII-like protein CutA does not support involvement in heavy metal tolerance and hints at a small-molecule carrying/signaling role.,Selim KA, Tremino L, Marco-Marin C, Alva V, Espinosa J, Contreras A, Hartmann MD, Forchhammer K, Rubio V FEBS J. 2020 Jun 29. doi: 10.1111/febs.15464. PMID:32599651<ref>PMID:32599651</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6t76" style="background-color:#fffaf0;"></div>

==See Also==
*[[CutA1 3D structures|CutA1 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Nostoc sp. PCC 7120 = FACHB-418]]
[[Category: Albrecht R]]
[[Category: Forchhammer K]]
[[Category: Hartmann MD]]
[[Category: Selim KA]]