1MNU

UNLIGANDED BACTERICIDAL ANTIBODY AGAINST NEISSERIA MENINGITIDIS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.231 

wwPDB Validation 3D Report Full Report


This is version 1.4 of the entry. See complete history

Literature

Bactericidal antibody recognition of meningococcal PorA by induced fit. Comparison of liganded and unliganded Fab structures.

van den Elsen, J.Vandeputte-Rutten, L.Kroon, J.Gros, P.

(1999) J.Biol.Chem. 274: 1495-1501

  • DOI: 10.1074/jbc.274.3.1495

  • PubMed Abstract: 
  • MN12H2 is a bactericidal antibody directed against outer membrane protein PorA epitope P1.16 of Neisseria meningitidis. Binding of MN12H2 to PorA at the meningococcal surface activates the classical complement pathway resulting in bacterial lysis. We ...

    MN12H2 is a bactericidal antibody directed against outer membrane protein PorA epitope P1.16 of Neisseria meningitidis. Binding of MN12H2 to PorA at the meningococcal surface activates the classical complement pathway resulting in bacterial lysis. We have determined the crystal structure of the unliganded MN12H2 Fab fragment in two different crystal forms and compared it with the structure of the Fab in complex with a P1.16-derived peptide. The unliganded Fabs have elbow bend angles of 155 degrees and 159 degrees, whereas the liganded Fab has a more closed elbow bend of 143 degrees. Substantial differences in quaternary and tertiary structure of the antigen binding site are observed between the unliganded and liganded MN12H2 Fab structures that can be attributed to peptide binding. The variable light and heavy chain interface of the liganded Fab is twisted by a 5 degrees rotation along an axis approximately perpendicular to the plane of the interface. Hypervariable loops H1, H2, and framework loop FR-H3 follow this rotation. The hypervariable loop H3 undergoes conformational changes but remains closely linked to hypervariable loop L1. In contrast with the binding site expansion seen in other Fab-peptide structures, the MN12H2 binding site is narrowed upon peptide binding due to the formation of a "false floor" mediated by arginine residue 101 of the light chain. These results indicate that PorA epitope P1.16 of N. meningitidis is recognized by the complement-activating antibody MN12H2 through induced fit, allowing the formation of a highly complementary immune complex.


    Organizational Affiliation

    Department of Crystal and Structural Chemistry, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (IGG2A-KAPPA ANTIBODY MN12H2 (LIGHT CHAIN))
L
219Mus musculusMutation(s): 0 
Gene Names: Igkc (Igk-C)
Find proteins for A2NHM3 (Mus musculus)
Go to UniProtKB:  A2NHM3
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
PROTEIN (IGG2A-KAPPA ANTIBODY MN12H2 (HEAVY CHAIN))
H
225Mus musculusMutation(s): 0 
Gene Names: Ighg
Find proteins for P01863 (Mus musculus)
Go to UniProtKB:  P01863
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
CD
Query on CD

Download SDF File 
Download CCD File 
L
CADMIUM ION
Cd
WLZRMCYVCSSEQC-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.270 
  • R-Value Work: 0.231 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 114.617α = 90.00
b = 85.862β = 122.69
c = 87.133γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
CNSphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-05-06
    Type: Initial release
  • Version 1.1: 2008-04-26
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2018-03-07
    Type: Data collection
  • Version 1.4: 2019-02-06
    Type: Data collection, Database references, Experimental preparation, Source and taxonomy