1YBJ

Structural and Dynamics studies of both apo and holo forms of the hemophore HasA

1YBJ の概要

• エントリーDOI: 10.2210/pdb1ybj/pdb
• 分子名称: Hemophore HasA (1 entity in total)
• 機能のキーワード: alpha+beta structure, curved anti-parallel beta-sheet, metal binding protein
• 由来する生物種: Serratia marcescens
• 細胞内の位置: Secreted: Q54450
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 18289.49

構造登録者

Wolff, N.,Izadi-Pruneyre, N.,Couprie, J.,Habeck, M.,Linge, J.,Rieping, W.,Wandersman, C.,Nilges, M.,Delepierre, M.,Lecroisey, A. (登録日: 2004-12-21, 公開日: 2005-12-27, 最終更新日: 2024-05-22)

主引用文献

Wolff, N.,Izadi-Pruneyre, N.,Couprie, J.,Habeck, M.,Linge, J.,Rieping, W.,Wandersman, C.,Nilges, M.,Delepierre, M.,Lecroisey, A.
Comparative analysis of structural and dynamic properties of the loaded and unloaded hemophore HasA: functional implications.
J.Mol.Biol., 376:517-525, 2008

PubMed Abstract: A heme-acquisition system present in several Gram-negative bacteria requires the secretion of hemophores. These extracellular carrier proteins capture heme and deliver it to specific outer membrane receptors. The Serratia marcescens HasA hemophore is a monodomain protein that binds heme with a very high affinity. Its alpha/beta structure, as that of its binding pocket, has no common features with other iron- or heme-binding proteins. Heme is held by two loops L1 and L2 and coordinated to iron by an unusual ligand pair, H32/Y75. Two independent regions of the hemophore beta-sheet are involved in HasA-HasR receptor interaction. Here, we report the 3-D NMR structure of apoHasA and the backbone dynamics of both loaded and unloaded hemophore. While the overall structure of HasA is very similar in the apo and holo forms, the hemophore presents a transition from an open to a closed form upon ligand binding, through a large movement, of up to 30 A, of loop L1 bearing H32. Comparison of loaded and unloaded HasA dynamics on different time scales reveals striking flexibility changes in the binding pocket. We propose a mechanism by which these structural and dynamic features provide the dual function of heme binding and release to the HasR receptor.

PubMed: 18164722
DOI: 10.1016/j.jmb.2007.11.072

実験手法

SOLUTION NMR