1OSY

Crystal structure of FIP-Fve fungal immunomodulatory protein

Summary for 1OSY

• Entry DOI: 10.2210/pdb1osy/pdb
• Descriptor: IMMUNOMODULATORY PROTEIN FIP-FVE, BROMIDE ION (3 entities in total)
• Functional Keywords: fungal protein, immunomodulatory, fibronectin fold, hemagglutination, lectin, sugar binding protein, immune system
• Biological source: Flammulina velutipes
• Total number of polymer chains: 2
• Total formula weight: 26760.95

Authors

Palasingam, P.,Joseph, J.S.,Seow, S.V.,Shai, V.,Robinson, H.,Chua, K.Y.,Kolatkar, P.R. (deposition date: 2003-03-20, release date: 2003-11-04, Last modification date: 2024-10-30)

Primary citation

Paaventhan, P.,Joseph, J.S.,Seow, S.V.,Vaday, S.,Robinson, H.,Chua, K.Y.,Kolatkar, P.R.
A 1.7A structure of Fve, a member of the new fungal immunomodulatory protein family
J.Mol.Biol., 332:461-470, 2003

PubMed Abstract: Fve, a major fruiting body protein from Flammulina velutipes, a mushroom possessing immunomodulatory activity, stimulates lymphocyte mitogenesis, suppresses systemic anaphylaxis reactions and edema, enhances transcription of IL-2, IFN-gamma and TNF-alpha, and hemagglutinates red blood cells. It appears to be a lectin with specificity for complex cell-surface carbohydrates. Fve is a non-covalently linked homodimer containing no Cys, His or Met residues. It shares sequence similarity only to the other fungal immunomodulatory proteins (FIPs) LZ-8, Gts, Vvo and Vvl, all of unknown structure. The 1.7A structure of Fve solved by single anomalous diffraction of NaBr-soaked crystals is novel: each monomer consists of an N-terminal alpha-helix followed by a fibronectin III (FNIII) fold. The FNIII fold is the first instance of "pseudo-h-type" topology, a transition between the seven beta-stranded s-type and the eight beta-stranded h-type topologies. The structure suggests that dimerization, critical for the activity of FIPs, occurs by 3-D domain swapping of the N-terminal helices and is stabilized predominantly by hydrophobic interactions. The structure of Fve is the first in this lectin family to be reported, and the first of an FNIII domain-containing protein of fungal origin.

PubMed: 12948495
DOI: 10.1016/S0022-2836(03)00923-9

Experimental method

X-RAY DIFFRACTION (1.7 Å)