1el4

<table><tr><td colspan='2'>[[1el4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Black_sea_hydrozoan Black sea hydrozoan]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EL4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EL4 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CTZ:C2-HYDROXY-COELENTERAZINE'>CTZ</scene></td></tr>

[[https://www.uniprot.org/uniprot/OBL_OBELO OBL_OBELO]] Ca(2+)-dependent bioluminescence photoprotein. Displays an emission peak at 470 nm (blue light). Trace amounts of calcium ion trigger the intramolecular oxidation of the chromophore, coelenterazine into coelenteramide and CO(2) with the concomitant emission of light.

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

The crystal structure of the photoprotein obelin (22.2 kDa) from Obelia longissima has been determined and refined to 1.7 A resolution. Contrary to the prediction of a peroxide, the noncovalently bound substrate, coelenterazine, has only a single oxygen atom bound at the C2-position. The protein-coelenterazine 2-oxy complex observed in the crystals is photo-active because, in the presence of calcium ion, bioluminescence emission within the crystal is observed. This structure represents only the second de novo protein structure determined using the anomalous scattering signal of the sulfur substructure in the crystal. The method used here is theoretically different from that used for crambin in 1981 (4.72 kDa) and represents a significant advancement in protein crystal structure determination.

Structure of the Ca2+-regulated photoprotein obelin at 1.7 A resolution determined directly from its sulfur substructure.,Liu ZJ, Vysotski ES, Chen CJ, Rose JP, Lee J, Wang BC Protein Sci. 2000 Nov;9(11):2085-93. PMID:11152120<ref>PMID:11152120</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

</div>

<div class="pdbe-citations 1el4" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: Black sea hydrozoan]]

[[Category: Lee, J]]

[[Category: Liu, Z J]]

[[Category: Rose, J]]

[[Category: Vysotski, E S]]

[[Category: Wang, B C]]

[[Category: Bioluminescence]]

[[Category: Sulfur anomalous scattering]]