PDBsum entry 2rdl

Hydrolase/hydrolase inhibitor

PDB id: 2rdl

Contents

Protein chains

226 a.a. *

Ligands

MSU-ALA-ALA-PRO-ALV-0QE ×2

SO4 ×4

Waters ×127

* Residue conservation analysis

PDB id:

2rdl

Name:

Hydrolase/hydrolase inhibitor

Title:

Hamster chymase 2

Structure:

Chymase 2. Chain: a, b. Engineered: yes. Methoxysuccinyl-ala-ala-pro-ala-chloromethylketone inhibitor. Chain: i, j. Engineered: yes

Source:

Mesocricetus auratus. Golden hamster. Organism_taxid: 10036. Expressed in: unidentified baculovirus. Expression_system_taxid: 10469. Synthetic: yes

Resolution:

2.50Å R-factor: 0.186 R-free: 0.253

Authors:

J.Spurlino,M.Abad,J.Kervinen

Key ref:

J.Kervinen et al. (2008). Structural basis for elastolytic substrate specificity in rodent alpha-chymases. J Biol Chem, 283, 427-436. PubMed id: 17981788 DOI: 10.1074/jbc.M707157200

Date:

24-Sep-07 Release date: 30-Oct-07

Protein chains

O70164  (O70164_MESAU) -  Chymase 2 from Mesocricetus auratus

Seq: 247 a.a.

Struc: 226 a.a.

DOI no: 10.1074/jbc.M707157200

J Biol Chem 283:427-436 (2008)

PubMed id: 17981788

Structural basis for elastolytic substrate specificity in rodent alpha-chymases.

J.Kervinen, M.Abad, C.Crysler, M.Kolpak, A.D.Mahan, J.A.Masucci, S.Bayoumy, M.D.Cummings, X.Yao, M.Olson, L.de Garavilla, L.Kuo, I.Deckman, J.Spurlino.

ABSTRACT

Divergence of substrate specificity within the context of a common structural framework represents an important mechanism by which new enzyme activity naturally evolves. We present enzymological and x-ray structural data for hamster chymase-2 (HAM2) that provides a detailed explanation for the unusual hydrolytic specificity of this rodent alpha-chymase. In enzymatic characterization, hamster chymase-1 (HAM1) showed typical chymase proteolytic activity. In contrast, HAM2 exhibited atypical substrate specificity, cleaving on the carboxyl side of the P1 substrate residues Ala and Val, characteristic of elastolytic rather than chymotryptic specificity. The 2.5-A resolution crystal structure of HAM2 complexed to the peptidyl inhibitor MeOSuc-Ala-Ala-Pro-Ala-chloromethylketone revealed a narrow and shallow S1 substrate binding pocket that accommodated only a small hydrophobic residue (e.g. Ala or Val). The different substrate specificities of HAM2 and HAM1 are explained by changes in four S1 substrate site residues (positions 189, 190, 216, and 226). Of these, Asn(189), Val(190), and Val(216) form an easily identifiable triplet in all known rodent alpha-chymases that can be used to predict elastolytic specificity for novel chymase-like sequences. Phylogenetic comparison defines guinea pig and rabbit chymases as the closest orthologs to rodent alpha-chymases.

Selected figure(s)

Figure 4.
FIGURE 4. Structural analysis of the catalytic cleft. A, accessible surface of molecules A (white-blue-red) and B (green-blue-red) in the asymmetric unit with MeOSuc-Ala-Ala-Pro-Ala-CMK shown for molecule A. B, semitransparent surface representation of the catalytic cleft of HAM2. The stick model in color-by-atom denotes MeOSuc-Ala-Ala-Pro-Ala-CMK bound to HAM2. Suc-Ala-Ala-Pro-Phe-CMK (magenta), covalently bound to the crystal structure of human chymase (37), is superimposed onto the HAM2 structure. Molecular figures were prepared with PyMOL (DeLano Scientific LLC, www.pymol.org).

Figure 5.
FIGURE 5. Schematic diagram of the hydrogen bond and other interactions between HAM2 and the inhibitor MeOSuc-Ala-Ala-Pro-Ala-CMK.

The above figures are reprinted by permission from the ASBMB: J Biol Chem (2008, 283, 427-436) copyright 2008.

Figures were selected by an automated process.