3S18

Crystal structure of a plant albumin from cicer arietinum showing hemagglutination

3S18 の概要

• エントリーDOI: 10.2210/pdb3s18/pdb
• 関連するPDBエントリー: 3S0L
• 分子名称: lectin, SULFATE ION, CALCIUM ION, ... (7 entities in total)
• 機能のキーワード: plant albumin and hemagglutination, b-propeller fold, hemagglutination, sugars, seeds, hemagglutinin, complex sugars, cicer arietinum lectin, sugar binding protein
• 由来する生物種: Cicer arietinum
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 52089.41

構造登録者

Sharma, U.,Suresh, C.G. (登録日: 2011-05-14, 公開日: 2011-07-13, 最終更新日: 2023-11-01)

主引用文献

Sharma, U.,Katre, U.V.,Suresh, C.G.
Crystal structure of a plant albumin from Cicer arietinum (chickpea) possessing hemopexin fold and hemagglutination activity
Planta, 2015

PubMed Abstract: Crystal structure of a reported PA2 albumin from Cicer arietinum shows that it belongs to hemopexin fold family, has four beta-propeller motifs and possesses hemagglutination activity, making it different from known legume lectins. A plant albumin (PA2) from Cicer arietinum, presumably a lectin (CAL) owing to its hemagglutination activity which is inhibited by complex sugars as well as glycoproteins such as fetuin, desialylated fetuin and fibrinogen. The three-dimensional structure of this homodimeric protein has been determined using X-ray crystallography at 2.2 Å in two crystal forms: orthorhombic (P21212) and trigonal (P3). The structure determined using molecular replacement method and refined in orthorhombic crystal form reached R-factors R free 22.6 % and R work 18.2 % and in trigonal form had 22.3 and 17.9 % in the resolution range of 20.0-2.2 and 35.3-2.2 Å, respectively. Interestingly, unlike the known legume lectin fold, the structure of this homodimeric hemagglutinin belonged to hemopexin fold that consisted of four-bladed β-propeller architecture. Each subunit has a central cavity forming a channel, inside of which is lined with hydrophobic residues. The channel also bears binding sites for ligands such as calcium, sodium and chloride ions, iodine atom in the case of iodine derivative and water molecules. However, none of these ligands seem important for the sugar recognition. No monosaccharide sugar specificity could be detected using hemagglutination inhibition. Chemical modification studies identified a potential sugar-binding site per subunit molecule. Comparison of C-alpha atom positions in subunit structures showed that the deviations between the two crystal forms were more with respect to blades I and IV. Differences also existed between subunits in two forms in terms of type and site of ligand binding.

PubMed: 25559942
DOI: 10.1007/s00425-014-2236-6

実験手法

X-RAY DIFFRACTION (2.2 Å)