2K9K

Molecular characterization of the tonb2 protein from vibrio anguillarum

2K9K の概要

• エントリーDOI: 10.2210/pdb2k9k/pdb
• 関連するPDBエントリー: 1U07 1XX3 2GRX 2GSK
• NMR情報: BMRB: 15988
• 分子名称: TonB2 (1 entity in total)
• 機能のキーワード: tonb2-ctd, metal transport
• 由来する生物種: Listonella anguillarum
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 11891.55

構造登録者

Lopez, C.S.,Peacock, R.S.,Crosa, J.H.,Vogel, H.J. (登録日: 2008-10-15, 公開日: 2008-11-18, 最終更新日: 2024-05-22)

主引用文献

Lopez, C.S.,Peacock, R.S.,Crosa, J.H.,Vogel, H.J.
Molecular characterization of the TonB2 protein from the fish pathogen Vibrio anguillarum.
Biochem.J., 418:49-59, 2009

PubMed Abstract: In the fish pathogen Vibrio anguillarum the TonB2 protein is essential for the uptake of the indigenous siderophore anguibactin. Here we describe deletion mutants and alanine replacements affecting the final six amino acids of TonB2. Deletions of more than two amino acids of the TonB2 C-terminus abolished ferric-anguibactin transport, whereas replacement of the last three residues resulted in a protein with wild-type transport properties. We have solved the high-resolution solution structure of the TonB2 C-terminal domain by NMR spectroscopy. The core of this domain (residues 121-206) has an alphabetabetaalphabeta structure, whereas residues 76-120 are flexible and extended. This overall folding topology is similar to the Escherichia coli TonB C-terminal domain, albeit with two differences: the beta4 strand found at the C-terminus of TonB is absent in TonB2, and loop 3 is extended by 9 A (0.9 nm) in TonB2. By examining several mutants, we determined that a complete loop 3 is not essential for TonB2 activity. Our results indicate that the beta4 strand of E. coli TonB is not required for activity of the TonB system across Gram-negative bacterial species. We have also determined, through NMR chemical-shift-perturbation experiments, that the E. coli TonB binds in vitro to the TonB box from the TonB2-dependent outer membrane transporter FatA; moreover, it can substitute in vivo for TonB2 during ferric-anguibactin transport in V. anguillarum. Unexpectedly, TonB2 did not bind in vitro to the FatA TonB-box region, suggesting that additional factors may be required to promote this interaction. Overall our results indicate that TonB2 is a representative of a different class of TonB proteins.

PubMed: 18973471
DOI: 10.1042/BJ20081462

実験手法

SOLUTION NMR