3H8T

Structure of Porphyromonas gingivalis heme-binding protein HmuY in complex with Heme

3H8T の概要

• エントリーDOI: 10.2210/pdb3h8t/pdb
• 分子名称: HmuY, PROTOPORPHYRIN IX CONTAINING FE, GLYCEROL, ... (5 entities in total)
• 機能のキーワード: hemophore, bacterial virulence factor, heme-binding protein, periodontitis
• 由来する生物種: Porphyromonas gingivalis (Bacteroides gingivalis)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 44624.85

構造登録者

Wojtowicz, H.,Guevara, T.,Tallant, C.,Olczak, M.,Sroka, A.,Potempa, J.,Sola, M.,Olczak, T.,Gomis-Ruth, F.X. (登録日: 2009-04-29, 公開日: 2009-05-12, 最終更新日: 2024-02-21)

主引用文献

Wojtowicz, H.,Guevara, T.,Tallant, C.,Olczak, M.,Sroka, A.,Potempa, J.,Sola, M.,Olczak, T.,Gomis-Ruth, F.X.
Unique structure and stability of HmuY, a novel heme-binding protein of Porphyromonas gingivalis
Plos Pathog., 5:e1000419-e1000419, 2009

PubMed Abstract: Infection, survival, and proliferation of pathogenic bacteria in humans depend on their capacity to impair host responses and acquire nutrients in a hostile environment. Among such nutrients is heme, a co-factor for oxygen storage, electron transport, photosynthesis, and redox biochemistry, which is indispensable for life. Porphyromonas gingivalis is the major human bacterial pathogen responsible for severe periodontitis. It recruits heme through HmuY, which sequesters heme from host carriers and delivers it to its cognate outer-membrane transporter, the TonB-dependent receptor HmuR. Here we report that heme binding does not significantly affect the secondary structure of HmuY. The crystal structure of heme-bound HmuY reveals a new all-beta fold mimicking a right hand. The thumb and fingers pinch heme iron through two apical histidine residues, giving rise to highly symmetric octahedral iron co-ordination. The tetrameric quaternary arrangement of the protein found in the crystal structure is consistent with experiments in solution. It shows that thumbs and fingertips, and, by extension, the bound heme groups, are shielded from competing heme-binding proteins from the host. This may also facilitate heme transport to HmuR for internalization. HmuY, both in its apo- and in its heme-bound forms, is resistant to proteolytic digestion by trypsin and the major secreted proteases of P. gingivalis, gingipains K and R. It is also stable against thermal and chemical denaturation. In conclusion, these studies reveal novel molecular properties of HmuY that are consistent with its role as a putative virulence factor during bacterial infection.

PubMed: 19424422
DOI: 10.1371/journal.ppat.1000419

実験手法

X-RAY DIFFRACTION (1.8 Å)