View source for 4nfe


==Human kallikrein-related peptidase 2 in complex with benzamidine==
<StructureSection load='4nfe' size='340' side='right'caption='[[4nfe]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4nfe]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4NFE OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4NFE FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=BEN:BENZAMIDINE'>BEN</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[4nff|4nff]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">KLK2 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 HUMAN])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Tissue_kallikrein Tissue kallikrein], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.35 3.4.21.35] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4nfe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4nfe OCA], [http://pdbe.org/4nfe PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=4nfe RCSB], [http://www.ebi.ac.uk/pdbsum/4nfe PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=4nfe ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/KLK2_HUMAN KLK2_HUMAN]] Glandular kallikreins cleave Met-Lys and Arg-Ser bonds in kininogen to release Lys-bradykinin. 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human kallikrein-related peptidase (KLK) 2 is a tryptic serine protease predominantly expressed in prostatic tissue and secreted into prostatic fluid, a major component of seminal fluid. Most likely, it activates and complements chymotryptic KLK3 (prostate-specific antigen) in cleaving seminal clotting proteins, resulting in sperm liquefaction. KLK2 belongs to the "classical" KLKs 1-3, which share an extended 99- or kallikrein loop near their non-primed substrate binding site. Here, we report the 1.9 A crystal structures of two KLK2-small molecule inhibitor complexes. In both structures, discontinuous electron density for the 99-loop indicates that this loop is largely disordered. We provide evidence that the 99-loop is responsible for two biochemical peculiarities of KLK2, i.e. reversible inhibition by micromolar Zn2+ concentrations and permanent inactivation by autocatalytic cleavage. Indeed, several 99-loop mutants of KLK2 displayed an altered susceptibility to Zn2+, which located the Zn2+ binding site at the 99-loop/active site interface. In addition, we identified an autolysis site between residues 95e and 95f in the 99-loop, whose elimination prevented the mature enzyme from limited autolysis and irreversible inactivation. An exhaustive comparison of KLK2 with related structures revealed that in the KLK family, the 99-, 148- and 220-loop exist in open and closed conformations, allowing or preventing substrate access, which extends the concept of conformational selection in trypsin-related proteases. Taken together, our novel biochemical and structural data on KLK2 identify its 99-loop as a key player in activity regulation.

Structure-Function Analyses of Human Kallikrein-Related Peptidase 2 Establish the 99-Loop as Master Regulator of Activity.,Skala W, Utzschneider DT, Magdolen V, Debela M, Guo S, Craik CS, Brandstetter H, Goettig P J Biol Chem. 2014 Oct 16. pii: jbc.M114.598201. PMID:25326387<ref>PMID:25326387</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4nfe" style="background-color:#fffaf0;"></div>

==See Also==
*[[Kallikrein|Kallikrein]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Large Structures]]
[[Category: Tissue kallikrein]]
[[Category: Brandstetter, H]]
[[Category: Goettig, P]]
[[Category: Magdolen, V]]
[[Category: Skala, W]]
[[Category: Chymotrypsin-like protease]]
[[Category: Extracellular]]
[[Category: Hydrolase]]
[[Category: Zinc binding]]