2JHM

Structure of globular heads of M-ficolin at neutral pH


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.52 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Structural Basis for Innate Immune Sensing by M-Ficolin and its Control by a Ph-Dependent Conformational Switch.

Garlatti, V.Martin, L.Gout, E.Reiser, J.B.Fujita, T.Arlaud, G.J.Thielens, N.M.Gaboriaud, C.

(2007) J Biol Chem 282: 35814

  • DOI: 10.1074/jbc.M705741200
  • Primary Citation of Related Structures:  
    2JHM, 2JHL, 2JHK, 2JHI, 2JHH

  • PubMed Abstract: 
  • Ficolins are soluble oligomeric proteins with lectin-like activity, assembled from collagen fibers prolonged by fibrinogen-like recognition domains. They act as innate immune sensors by recognizing conserved molecular markers exposed on microbial surfaces and thereby triggering effector mechanisms such as enhanced phagocytosis and inflammation ...

    Ficolins are soluble oligomeric proteins with lectin-like activity, assembled from collagen fibers prolonged by fibrinogen-like recognition domains. They act as innate immune sensors by recognizing conserved molecular markers exposed on microbial surfaces and thereby triggering effector mechanisms such as enhanced phagocytosis and inflammation. In humans, L- and H-ficolins have been characterized in plasma, whereas a third species, M-ficolin, is secreted by monocytes and macrophages. To decipher the molecular mechanisms underlying their recognition properties, we previously solved the structures of the recognition domains of L- and H-ficolins, in complex with various model ligands (Garlatti, V., Belloy, N., Martin, L., Lacroix, M., Matsushita, M., Endo, Y., Fujita, T., Fontecilla-Camps, J. C., Arlaud, G. J., Thielens, N. M., and Gaboriaud, C. (2007) EMBO J. 24, 623-633). We now report the ligand-bound crystal structures of the recognition domain of M-ficolin, determined at high resolution (1.75-1.8 A), which provides the first structural insights into its binding properties. Interaction with acetylated carbohydrates differs from the one previously described for L-ficolin. This study also reveals the structural determinants for binding to sialylated compounds, a property restricted to human M-ficolin and its mouse counterpart, ficolin B. Finally, comparison between the ligand-bound structures obtained at neutral pH and nonbinding conformations observed at pH 5.6 reveals how the ligand binding site is dislocated at acidic pH. This means that the binding function of M-ficolin is subject to a pH-sensitive conformational switch. Considering that the homologous ficolin B is found in the lysosomes of activated macrophages (Runza, V. L., Hehlgans, T., Echtenacher, B., Zahringer, U., Schwaeble, W. J., and Mannel, D. N. (2006) J. Endotoxin Res. 12, 120-126), we propose that this switch could play a physiological role in such acidic compartments.


    Organizational Affiliation

    Laboratoire de Cristallographie et Cristallogénèse des Protéines, Institut de Biologie Structurale Jean-Pierre Ebel, Commissariat à l'Energie Atomique-CNRS-Université Joseph Fourier, 38027 Grenoble, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
FICOLIN-1A [auth F]218Homo sapiensMutation(s): 0 
Gene Names: FCN1FCNM
Find proteins for O00602 (Homo sapiens)
Explore O00602 
Go to UniProtKB:  O00602
NIH Common Fund Data Resources
PHAROS:  O00602
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
EPE
Query on EPE

Download Ideal Coordinates CCD File 
C [auth F]4-(2-HYDROXYETHYL)-1-PIPERAZINE ETHANESULFONIC ACID
C8 H18 N2 O4 S
JKMHFZQWWAIEOD-UHFFFAOYSA-N
 Ligand Interaction
IPA
Query on IPA

Download Ideal Coordinates CCD File 
D [auth F]ISOPROPYL ALCOHOL
C3 H8 O
KFZMGEQAYNKOFK-UHFFFAOYSA-N
 Ligand Interaction
CA
Query on CA

Download Ideal Coordinates CCD File 
B [auth F]CALCIUM ION
Ca
BHPQYMZQTOCNFJ-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.52 Å
  • R-Value Free: 0.207 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.184 
  • Space Group: H 3
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 73.709α = 90
b = 73.709β = 90
c = 124.605γ = 120
Software Package:
Software NamePurpose
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling
PHASERphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-10-09
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2019-04-03
    Changes: Data collection, Other, Source and taxonomy