View source for 6mmd


==Photoactive Yellow Protein with 3,5-dichlorotyrosine substituted at position 42==
<StructureSection load='6mmd' size='340' side='right'caption='[[6mmd]], [[Resolution|resolution]] 1.23&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6mmd]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Halorhodospira_halophila Halorhodospira halophila]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6MMD OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6MMD 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]] 1.228&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=2LT:3,5-DICHLORO-L-TYROSINE'>2LT</scene>, <scene name='pdbligand=HC4:4-HYDROXYCINNAMIC+ACID'>HC4</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=6mmd FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6mmd OCA], [https://pdbe.org/6mmd PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6mmd RCSB], [https://www.ebi.ac.uk/pdbsum/6mmd PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6mmd ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/PYP_HALHA PYP_HALHA] Photoactive blue light protein. Probably functions as a photoreceptor for a negative phototaxis response.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Photoactive yellow protein (PYP) is a small photoreceptor protein that has two unusually short hydrogen bonds between the deprotonated p-coumaric acid chromophore and two amino acids, a tyrosine and a glutamic acid. This has led to considerable debate as to whether the glutamic acid-chromophore hydrogen bond is a low barrier hydrogen bond, with conflicting results in the literature. We have modified the p Ka of the tyrosine by amber suppression and of the chromophore by chemical substitution. X-ray crystal structures of these modified proteins are nearly identical to the wild-type protein, so the heavy atom distance between proton donor and acceptor is maintained, even though these modifications change the relative proton affinity between donor and acceptor. Despite a considerable change in relative proton affinity, the NMR chemical shifts of the hydrogen-bonded protons are only moderately affected. QM/MM calculations were used to explore the protons' potential energy surface and connect the calculated proton position with empirically measured proton chemical shifts. The results are inconsistent with a low barrier hydrogen bond but in all cases are consistent with a localized proton, suggesting an ionic hydrogen bond rather than a low barrier hydrogen bond.

Perturbation of Short Hydrogen Bonds in Photoactive Yellow Protein via Noncanonical Amino Acid Incorporation.,Thomson B, Both J, Wu Y, Parrish RM, Martinez TJ, Boxer SG J Phys Chem B. 2019 May 31. doi: 10.1021/acs.jpcb.9b01571. PMID:31117606<ref>PMID:31117606</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6mmd" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Halorhodospira halophila]]
[[Category: Large Structures]]
[[Category: Both J]]
[[Category: Boxer SG]]
[[Category: Martinez T]]
[[Category: Parrish RM]]
[[Category: Thomson BD]]
[[Category: Wu Y]]