1sel

<table><tr><td colspan='2'>[[1sel]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/"vibrio_subtilis"_ehrenberg_1835 "vibrio subtilis" ehrenberg 1835]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1SEL OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1SEL FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=SE7:2-AMINO-3-SELENINO-PROPIONIC+ACID'>SE7</scene></td></tr>

[[https://www.uniprot.org/uniprot/SUBT_BACLI SUBT_BACLI]] Subtilisin is an extracellular alkaline serine protease, it catalyzes the hydrolysis of proteins and peptide amides.

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== Publication Abstract from PubMed ==

The three-dimensional structure of selenosubtilisin, an artificial selenoenzyme, has been solved at 2.0-A resolution by the method of molecular replacement. Selenosubtilisin is a chemical derivative of the bacterial serine protease subtilisin in which the catalytically essential serine residue has been replaced with a selenocysteine. Its unique hydrolytic and redox properties reflect the intrinsic chemical reactivity of the selenium prosthetic group. Structural analysis of the modified protein reveals that the selenium moiety is selectively incorporated into the side chain of residue 221 and confirms the seleninic acid oxidation state expected from treatment of the enzyme with hydrogen peroxide prior to crystallization. Although the seleninic acid replaces the essential nucleophile in the enzyme's catalytic triad and introduces a negative charge into the active site, the interaction between His64 and Asp32 is not altered by the modification. Hydrogen bonds from the oxygen atoms of the seleninic acid to His64 and to Asn155 in the oxyanion hole confine the prosthetic group to a single well-defined conformation within the active site. These interactions thus provide a structural basis for understanding the seleninic acid's unusually low pKa, the enzyme's relatively sluggish rate of reaction with thiols, and its much more efficient peroxidase activity. Aside from the active site region, the structure of the protein is essentially the same as that previously reported for native subtilisin Carlsberg, indicating the viability of chemical modification strategies for incorporating site-specific changes into the protein backbone. Comparison of the three-dimensional structures of selenosubtilisin and glutathione peroxidase, an important naturally occurring selenoenzyme, provides the means to evaluate how the function of the selenium prosthetic group varies with molecular context.

Crystal structure of selenosubtilisin at 2.0-A resolution.,Syed R, Wu ZP, Hogle JM, Hilvert D Biochemistry. 1993 Jun 22;32(24):6157-64. PMID:8512925<ref>PMID:8512925</ref>

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

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

[[Category: Vibrio subtilis ehrenberg 1835]]

[[Category: Hilvert, D]]

[[Category: Hogle, J M]]

[[Category: Syed, R]]