PDBsum entry: 1p9g

Antifungal protein

PDB id: 1p9g

Contents

Protein chain

41 a.a.

Ligands

ACT ×2

Waters ×64

PDB id:

1p9g

Name:

Antifungal protein

Title:

Crystal structure of a novel antifungal protein distinct with five disulfide bridges from ecommia ulmoides oliver at atomic resolution

Structure:

Eafp 2. Chain: a

Source:

Eucommia ulmoides. Organism_taxid: 4392. Tissue: tree bark

Resolution:

0.84Å R-factor: 0.068 R-free: 0.079

Authors:

Y.Xiang,R.H.Huang,X.Z.Liu,D.C.Wang

Key ref:

Y.Xiang et al. (2004). Crystal structure of a novel antifungal protein distinct with five disulfide bridges from Eucommia ulmoides Oliver at an atomic resolution. J Struct Biol, 148, 86-97. PubMed id: 15363789 DOI: 10.1016/j.jsb.2004.04.002

Date:

12-May-03 Release date: 01-Jun-04

Protein chain

P83597  (EAP2_EUCUL) -  Antifungal peptide 2

Seq: 41 a.a.

Struc: 41 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

 Gene Ontology (GO) functional annotation 

• Biological process: killing of cells of another organism (3 terms)
• Biochemical function: chitin binding (1 term)

DOI no: 10.1016/j.jsb.2004.04.002

J Struct Biol 148:86-97 (2004)

PubMed id: 15363789

Crystal structure of a novel antifungal protein distinct with five disulfide bridges from Eucommia ulmoides Oliver at an atomic resolution.

Y.Xiang, R.H.Huang, X.Z.Liu, Y.Zhang, D.C.Wang.

ABSTRACT

EAFP2 is a novel antifungal protein isolated from the bark of the tree Eucommia ulmoides Oliver. It consists of 41 residues and is characterized with a five-disulfide motif and the inhibitory effects on the growth of both cell wall chitin-containing and chitin-free fungi. The crystal structure of EAFP2 at an atomic resolution of 0.84 A has been determined by using Shake-and-Bake direct methods with the program SnB. The phases obtained were of sufficient quality to permit the initial model built automatically and the structural refinement carried out using anisotropic displacement parameters resulted in a final crystallographic R factor of 6.8%. In the resulting structural model, all non-hydrogen protein atoms including an unusual pyroglutamyl acid residue at the N-terminal can fit to the articulated electron densities with one centre and more than 65% of the hydrogen atoms in the protein can be observed as individual peaks in the difference map. The general fold of EAFP2 is composed of a 3(10) helix (Cys3-Arg6), an alpha-helix (Ala27-Cys31) and a three-stranded antiparallel beta-sheet (Cys16-Ser18, Cys23-Ser25, and Cys35-Cys37) and cross-linked by five disulfide bridges. The tertiary structure of EAFP2 can be divided into two structural sectors, A and B. Sector A composed of residues 11-30 adopts a conformation similar to the chitin-binding domain in the hevein-like proteins and features a hydrophobic surface embraced a chitin-binding site (Tyr20, 22, 29, and Ser18). The distinct disulfide bridge Cys7-Cys37 connects the N-terminal ten residues with the C-terminal segment 35-41 to form the sector B, which features a cationic surface distributing all four positively charged residues, Arg6, 9, 36, and 40. Based on these structural features, the possible structural basis of the functional properties of EAFP2 is discussed.