3SAO

The Siderocalin Ex-FABP functions through dual ligand specificities

3SAO の概要

• エントリーDOI: 10.2210/pdb3sao/pdb
• 分子名称: Extracellular fatty acid-binding protein, (2R)-2-hydroxy-3-(phosphonooxy)propyl tetradecanoate, 2,3-DIHYDROXY-BENZOIC ACID, ... (6 entities in total)
• 機能のキーワード: beta-barrel, siderophore binding protein, transport protein
• 由来する生物種: Gallus gallus (chicken)
• 細胞内の位置: Secreted: P21760
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 37464.50

構造登録者

Correnti, C.,Strong, R.K.,Clifton, M.C. (登録日: 2011-06-03, 公開日: 2011-12-28, 最終更新日: 2023-09-13)

主引用文献

Correnti, C.,Clifton, M.C.,Abergel, R.J.,Allred, B.,Hoette, T.M.,Ruiz, M.,Cancedda, R.,Raymond, K.N.,Descalzi, F.,Strong, R.K.
Galline Ex-FABP Is an Antibacterial Siderocalin and a Lysophosphatidic Acid Sensor Functioning through Dual Ligand Specificities.
Structure, 19:1796-1806, 2011

PubMed Abstract: Galline Ex-FABP was identified as another candidate antibacterial, catecholate siderophore binding lipocalin (siderocalin) based on structural parallels with the family archetype, mammalian Siderocalin. Binding assays show that Ex-FABP retains iron in a siderophore-dependent manner in both hypertrophic and dedifferentiated chondrocytes, where Ex-FABP expression is induced after treatment with proinflammatory agents, and specifically binds ferric complexes of enterobactin, parabactin, bacillibactin and, unexpectedly, monoglucosylated enterobactin, which does not bind to Siderocalin. Growth arrest assays functionally confirm the bacteriostatic effect of Ex-FABP in vitro under iron-limiting conditions. The 1.8 Å crystal structure of Ex-FABP explains the expanded specificity, but also surprisingly reveals an extended, multi-chambered cavity extending through the protein and encompassing two separate ligand specificities, one for bacterial siderophores (as in Siderocalin) at one end and one specifically binding copurified lysophosphatidic acid, a potent cell signaling molecule, at the other end, suggesting Ex-FABP employs dual functionalities to explain its diverse endogenous activities.

PubMed: 22153502
DOI: 10.1016/j.str.2011.09.019

実験手法

X-RAY DIFFRACTION (1.8 Å)