Biological Assembly 1  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 1 assigned by authors.

Biological Assembly 2  

 3D View: Structure | Electron Density | Ligand Interaction

Standalone Viewers  
Protein Workshop | Ligand Explorer

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A 

Biological assembly 2 assigned by authors.

Macromolecule Content

• Total Structure Weight: 72203.26 
• Atom Count: 4870 
• Residue Count: 656 
• Unique protein chains: 1

1Q3X

Crystal structure of the catalytic region of human MASP-2

• DOI: 10.2210/pdb1Q3X/pdb

• Classification: HYDROLASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)


• Deposited: 2003-08-01 Released: 2004-08-03 
• Deposition Author(s): Harmat, V., Gal, P., Kardos, J., Szilagyi, K., Ambrus, G., Naray-Szabo, G., Zavodszky, P.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.23 Å
• R-Value Free: 0.224 
• R-Value Work: 0.174 

Literature

The structure of MBL-associated serine protease-2 reveals that identical substrate specificities of C1s and MASP-2 are realized through different sets of enzyme-substrate interactions

Harmat, V., Gal, P., Kardos, J., Szilagyi, K., Ambrus, G., Vegh, B., Naray-Szabo, G., Zavodsky, P.

(2004) J.Mol.Biol. 342: 1533-1546

• PubMed: 15364579 
• DOI: 10.1016/j.jmb.2004.07.014
• Also Cited By: 1ZJK


• PubMed Abstract: 
  

A family of serine proteases mediates the proteolytic cascades of several defense mechanisms in vertebrates, such as the complement system, blood coagulation and fibrinolysis. These proteases usually form large complexes with other glycoproteins. Their common features are their modular structures and restricted substrate specificities. The lectin pathway of complement, where mannose-binding lectin (MBL) recognizes the carbohydrate structures on pathogens, is activated by mannose-binding lectin-associated serine protease-2 (MASP-2). We present the 2.25A resolution structure of the catalytic fragment of MASP-2 encompassing the second complement control protein module (CCP2) and the serine protease (SP) domain. The CCP2 module stabilizes the structure of the SP domain as demonstrated by differential scanning calorimetry measurements. The asymmetric unit contains two molecules with different CCP-SP domain orientations, reflecting increased modular flexibility at the CCP2/SP joint. This flexibility may partly explain the ability of the MASP-2 dimer to perform all of its functions alone, whereas the same functions are mediated by the much larger C1r2-C1s2 tetramer in the C1 complex of the classical pathway. The main scaffold of the MASP-2 SP domain is chymotrypsin-like. Eight surface loops determine the S1 and other subsite specificities. Surprisingly, some surface loops of MASP-2, e.g. loop 1 and loop 2, which form the S1 pocket are similar to those of trypsin, and show significant differences if compared with those of C1s, indicating that the nearly identical substrate specificities of C1s and MASP-2 are realized through different sets of enzyme-substrate interactions.

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Related Citations: 

• Natural substrates and inhibitors of mannan-binding lectin-associated serine protease 1 and 2: A study on recombinant catalytic fragments
  Ambrus, G.,Gal, P.,Kojima, M.,Szilagyi, K.,Balczer, J.,Antal, J.,Graf, L.,Laich, A.,Moffat, B.E.,Schwaelbe, W.,Sim, R.B.,Zvodszky, P.
  (2003) J.Immunol. 170: 1374
• Crystal structure of the catalytic domain of human complement C1s: a serine protease with a handle
  Gaboriaud, C.,Rossi, V.,Bally, I.,Arlaud, G.J.,Fontecilla-Camps, J.C.
  (2000) Embo J. 19: 1755




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Organizational Affiliation: 

Protein Modeling Group, Hungarian Academy of Sciences, Eötvös Loránd University, Pázmány Péter sétány. 1A, H-1117 Budapest, Hungary.

Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details
Mannan-binding lectin serine protease 2	A, B	328	Homo sapiens	Mutation(s): 0  Gene Names: MASP2 EC: 3.4.21.104
Find proteins for O00187 (Homo sapiens) Go to Gene View: MASP2 Go to UniProtKB:  O00187

Small Molecules

Ligands 2 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram & Interactions
NA	A, B	SODIUM ION Na FKNQFGJONOIPTF-UHFFFAOYSA-N
GOL	A, B	GLYCEROL GLYCERIN; PROPANE-1,2,3-TRIOL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.23 Å
• R-Value Free: 0.224 
• R-Value Work: 0.174 
• Space Group: P 1

Unit Cell:

Length (Å)	Angle (°)
a = 40.950	α = 96.44
b = 41.521	β = 91.77
c = 102.994	γ = 119.52

Software Package:

Software Name	Purpose
BEAST	phasing
REFMAC	refinement
MOSFLM	data reduction
CCP4	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2003-08-01 
• Released Date: 2004-08-03 
• Deposition Author(s): Harmat, V., Gal, P., Kardos, J., Szilagyi, K., Ambrus, G., Naray-Szabo, G., Zavodszky, P.

Revision History 

• Version 1.0: 2004-08-03
  Type: Initial release
• Version 1.1: 2008-04-29
  Type: Version format compliance
• Version 1.2: 2011-07-13
  Type: Advisory, Version format compliance