NMR structure of the C-terminal domain of TonB protein from Pseudomonas aeruginosa

PeerJ

article

Jesper S. Oeemig¹  O.H. Samuli Ollila¹  Hideo Iwaï¹ 

[1] Research Program in Structural Biology and Biophysics, Institute of Biotechnology, University of Helsinki;VIB Center for Structural Biology, Vlaams Instituut voor Biotechnologie ,(VIB), Vrije Universiteit Brussel;Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic

关键词: TonB;    NMR;    NMR structure;    15N relaxation;    Molecular dynamics;    BtuB;    Pseudomonas aeruginosa;    TonB-dependent energy transduction;    Protein structure;    Outer membrane transporter;   

DOI  :  10.7717/peerj.5412

学科分类：社会科学、人文和艺术（综合）

来源: Inra

【 摘 要 】

The TonB protein plays an essential role in the energy transduction system to drive active transport across the outer membrane (OM) using the proton-motive force of the cytoplasmic membrane of Gram-negative bacteria. The C-terminal domain (CTD) of TonB protein is known to interact with the conserved TonB box motif of TonB-dependent OM transporters, which likely induces structural changes in the OM transporters. Several distinct conformations of differently dissected CTDs of Escherichia coli TonB have been previously reported. Here we determined the solution NMR structure of a 96-residue fragment of Pseudomonas aeruginosa TonB (PaTonB-96). The structure shows a monomeric structure with the flexible C-terminal region (residues 338–342), different from the NMR structure of E. coli TonB (EcTonB-137). The extended and flexible C-terminal residues are confirmed by 15N relaxation analysis and molecular dynamics simulation. We created models for the PaTonB-96/TonB box interaction and propose that the internal fluctuations of PaTonB-96 makes it more accessible for the interactions with the TonB box and possibly plays a role in disrupting the plug domain of the TonB-dependent OM transporters.

【 授权许可】

CC BY