2PSX

Crystal Structure of Human Kallikrein 5 in complex with Leupeptin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.221 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural basis of the zinc inhibition of human tissue kallikrein 5.

Debela, M.Goettig, P.Magdolen, V.Huber, R.Schechter, N.M.Bode, W.

(2007) J.Mol.Biol. 373: 1017-1031

  • DOI: 10.1016/j.jmb.2007.08.042
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Human kallikrein 5 (hK5) is a member of the tissue kallikrein family of serine peptidases. It has trypsin-like substrate specificity, is inhibited by metal ions, and is abundantly expressed in human skin, where it is believed to play a central role i ...

    Human kallikrein 5 (hK5) is a member of the tissue kallikrein family of serine peptidases. It has trypsin-like substrate specificity, is inhibited by metal ions, and is abundantly expressed in human skin, where it is believed to play a central role in desquamation. To further understand the interaction of hK5 with substrates and metal ions, active recombinant hK5 was crystallized in complex with the tripeptidyl aldehyde inhibitor leupeptin, and structures at 2.3 A resolution were obtained with and without Zn2+. While the overall structure and the specificity of S1 pocket for basic side-chains were similar to that of hK4, a closely related family member, both differed in their interaction with Zn2+. Unlike hK4, the 75-loop of hK5 is not structured to bind a Zn2+. Instead, Zn2+ binds adjacent to the active site, becoming coordinated by the imidazole rings of His99 and His96 not present in hK4. This zinc binding is accompanied by a large shift in the backbone conformation of the 99-loop and by large movements of both His side-chains. Modeling studies show that in the absence of bound leupeptin, Zn2+ is likely further coordinated by the imidazolyl side-chain of the catalytic His57 which can, similar to equivalent His57 imidazole groups in the related rat kallikrein proteinase tonin and in an engineered metal-binding rat trypsin, rotate out of its triad position to provide the third co-ordination site of the bound Zn2+, rendering Zn2+-bound hK5 inactive. In solution, this mode of binding likely occurs in the presence of free and substrate saturated hK5, as kinetic analyses of Zn2+ inhibition indicate a non-competitive mechanism. Supporting the His57 re-orientation, Zn2+ does not fully inhibit hK5 hydrolysis of tripeptidyl substrates containing a P2-His residue. The P2 and His57 imidazole groups would lie next to each other in the enzyme-substrate complex, indicating that incomplete inhibition is due to competition between both imidazole groups for Zn2+. The His96-99-57 triad is thus suggested to be responsible for the Zn2+-mediated inhibition of hK5 catalysis.


    Organizational Affiliation

    Max-Planck-Institut für Biochemie, Proteinase Research Group, Am Klopferspitz 18, 82152 Martinsried, Germany.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Kallikrein-5
A
227Homo sapiensMutation(s): 0 
Gene Names: KLK5 (SCTE)
EC: 3.4.21.-
Find proteins for Q9Y337 (Homo sapiens)
Go to Gene View: KLK5
Go to UniProtKB:  Q9Y337
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
LEUPEPTIN
B
4N/AMutation(s): 0 
Protein Feature View is not available: No corresponding UniProt sequence found.
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download SDF File 
Download CCD File 
C
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Biologically Interesting Molecules 1 Unique
IDChainsNameType/Class2D Diagram3D Interactions
PRD_000216 (SVC)
Query on PRD_000216
BLEUPEPTINOligopeptide / Enzyme inhibitor

--

Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.3 Å
  • R-Value Free: 0.269 
  • R-Value Work: 0.221 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 125.219α = 90.00
b = 67.284β = 94.35
c = 39.916γ = 90.00
Software Package:
Software NamePurpose
LABVIEWdata collection
CNSrefinement
SCALEPACKdata scaling
PHASERphasing
DENZOdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-09-11
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary, Version format compliance
  • Version 1.2: 2012-12-12
    Type: Other