2Q8P

Crystal Structure of selenomethionine labelled S. aureus IsdE complexed with heme

2Q8P の概要

• エントリーDOI: 10.2210/pdb2q8p/pdb
• 関連するPDBエントリー: 2Q8Q
• 分子名称: Iron-regulated surface determinant E, PROTOPORPHYRIN IX CONTAINING FE (3 entities in total)
• 機能のキーワード: helical backbone metal receptor superfamily, metal transport
• 由来する生物種: Staphylococcus aureus subsp. aureus
• 細胞内の位置: Cell membrane ; Lipid-anchor : Q7A652
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 30728.93

構造登録者

Grigg, J.C.,Murphy, M.E. (登録日: 2007-06-11, 公開日: 2007-07-31, 最終更新日: 2024-11-20)

主引用文献

Grigg, J.C.,Vermeiren, C.L.,Heinrichs, D.E.,Murphy, M.E.
Heme Coordination by Staphylococcus aureus IsdE.
J.Biol.Chem., 282:28815-28822, 2007

PubMed Abstract: Staphylococcus aureus is a Gram-positive bacterial pathogen and a leading cause of hospital acquired infections. Because the free iron concentration in the human body is too low to support growth, S. aureus must acquire iron from host sources. Heme iron is the most prevalent iron reservoir in the human body and a predominant source of iron for S. aureus. The iron-regulated surface determinant (Isd) system removes heme from host heme proteins and transfers it to IsdE, the cognate substrate-binding lipoprotein of an ATP-binding cassette transporter, for import and subsequent degradation. Herein, we report the crystal structure of the soluble portion of the IsdE lipoprotein in complex with heme. The structure reveals a bi-lobed topology formed by an N- and C-terminal domain bridged by a single alpha-helix. The structure places IsdE as a member of the helical backbone metal receptor superfamily. A six-coordinate heme molecule is bound in the groove established at the domain interface, and the heme iron is coordinated in a novel fashion for heme transporters by Met(78) and His(229). Both heme propionate groups are secured by H-bonds to IsdE main chain and side chain groups. Of these residues, His(229) is essential for IsdE-mediated heme uptake by S. aureus when growth on heme as a sole iron source is measured. Multiple sequence alignments of homologues from several other Gram-positive bacteria, including the human pathogens pyogenes, Bacillus anthracis, and Listeria monocytogenes, suggest that these other systems function equivalently to S. aureus IsdE with respect to heme binding and transport.

PubMed: 17666394
DOI: 10.1074/jbc.M704602200

実験手法

X-RAY DIFFRACTION (1.95 Å)