interaction of the Escherichia coli protein SlyD with nickel ions illuminates the mechanism of regulation of its peptidyl-prolyl isomerase activity

• Published in: The FEBS journal Vol. 276; no. 16; pp. 4529 - 4544
• Main Authors: Martino, Luigi, He, Yangzi, Hands-Taylor, Katherine L.D, Valentine, Elizabeth R, Kelly, Geoff, Giancola, Concetta, Conte, Maria R
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.08.2009; Blackwell Publishing Ltd
• Subjects: Binding sites; Biochemistry; Calorimetry; Catalytic Domain; Cellular biology; E coli; Escherichia coli; Escherichia coli Proteins - metabolism; FK506-binding protein (FKBP); Magnetic Resonance Spectroscopy; Molecular biology; nickel; Nickel - metabolism; peptidyl-prolyl cis-trans isomerase (PPIase); Peptidylprolyl Isomerase - metabolism; Protein Conformation; Protein folding; Protein Structure, Secondary; Proteins; SlyD; Solutions; structure; Thermodynamics
• ISSN: 1742-464X; 1742-4658
• DOI: 10.1111/j.1742-4658.2009.07159.x

The sensitive to lysis D (SlyD) protein from Escherichia coli is related to the FK506-binding protein family, and it harbours both peptidyl-prolyl cis-trans isomerase (PPIase) and chaperone-like activity, preventing aggregation and promoting the correct folding of other proteins. Whereas a functional role of SlyD as a protein-folding catalyst in vivo remains unclear, SlyD has been shown to be an essential component for [Ni-Fe]-hydrogenase metallocentre assembly in bacteria. Interestingly, the isomerase activity of SlyD is uniquely modulated by nickel ions, which possibly regulate its functions in response to external stimuli. In this work, we investigated the solution structure of SlyD and its interaction with nickel ions, enabling us to gain insights into the molecular mechanism of this regulation. We have revealed that the PPIase module of SlyD contains an additional C-terminal α-helix packed against the catalytic site of the domain; unexpectedly, our results show that the interaction of SlyD with nickel ions entails participation of the novel structural features of the PPIase domain, eliciting structural alterations of the catalytic pocket. We suggest that such conformational rearrangements upon metal binding underlie the ability of nickel ions to regulate the isomerase activity of SlyD.