Abstract
Pseudomonas aeruginosa secretes an epoxide hydrolase with catalytic activity that triggers degradation of the cystic fibrosis transmembrane conductance regulator (CFTR) and perturbs other host defense networks. Targets of this CFTR inhibitory factor (Cif) are largely unknown, but include an epoxy-fatty acid. In this class of signaling molecules, chirality can be an important determinant of physiological output and potency. Here we explore the active-site chemistry of this two-step α/β-hydrolase and its implications for an emerging class of virulence enzymes. In combination with hydrolysis data, crystal structures of 15 trapped hydroxyalkyl-enzyme intermediates reveal the stereochemical basis of Cif's substrate specificity, as well as its regioisomeric and enantiomeric preferences. The structures also reveal distinct sets of conformational changes that enable the active site to expand dramatically in two directions, accommodating a surprising array of potential physiological epoxide targets. These new substrates may contribute to Cif's diverse effects in vivo, and thus to the success of P. aeruginosa and other pathogens during infection. Hvorecny et al. crystallized covalent intermediates of the epoxide hydrolase virulence factor Cif. The structures collectively illuminate Cif's stereospecificity and uncover a new set of fatty acid substrates. Cif can thus target key host immune signals, exacerbating the damage caused by opportunistic pathogens such as P. aeruginosa.
| Original language | English (US) |
|---|---|
| Journal | Structure |
| DOIs | |
| State | Accepted/In press - Dec 21 2016 |
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Keywords
- Enzyme stereospecificity
- Epoxide hydrolase
- Epoxy-fatty acids
- Hydroxyalkyl-enzyme intermediate
- Pseudomonas aeruginosa
- Structure-function relationships
- Virulence factor
- X-ray crystallography
ASJC Scopus subject areas
- Structural Biology
- Molecular Biology
Cite this
Active-Site Flexibility and Substrate Specificity in a Bacterial Virulence Factor : Crystallographic Snapshots of an Epoxide Hydrolase. / Hvorecny, Kelli L.; Bahl, Christopher D.; Kitamura, Seiya; Lee, Kin Sing Stephen; Hammock, Bruce D.; Morisseau, Christophe; Madden, Dean R.
In: Structure, 21.12.2016.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Active-Site Flexibility and Substrate Specificity in a Bacterial Virulence Factor
T2 - Crystallographic Snapshots of an Epoxide Hydrolase
AU - Hvorecny, Kelli L.
AU - Bahl, Christopher D.
AU - Kitamura, Seiya
AU - Lee, Kin Sing Stephen
AU - Hammock, Bruce D.
AU - Morisseau, Christophe
AU - Madden, Dean R.
PY - 2016/12/21
Y1 - 2016/12/21
N2 - Pseudomonas aeruginosa secretes an epoxide hydrolase with catalytic activity that triggers degradation of the cystic fibrosis transmembrane conductance regulator (CFTR) and perturbs other host defense networks. Targets of this CFTR inhibitory factor (Cif) are largely unknown, but include an epoxy-fatty acid. In this class of signaling molecules, chirality can be an important determinant of physiological output and potency. Here we explore the active-site chemistry of this two-step α/β-hydrolase and its implications for an emerging class of virulence enzymes. In combination with hydrolysis data, crystal structures of 15 trapped hydroxyalkyl-enzyme intermediates reveal the stereochemical basis of Cif's substrate specificity, as well as its regioisomeric and enantiomeric preferences. The structures also reveal distinct sets of conformational changes that enable the active site to expand dramatically in two directions, accommodating a surprising array of potential physiological epoxide targets. These new substrates may contribute to Cif's diverse effects in vivo, and thus to the success of P. aeruginosa and other pathogens during infection. Hvorecny et al. crystallized covalent intermediates of the epoxide hydrolase virulence factor Cif. The structures collectively illuminate Cif's stereospecificity and uncover a new set of fatty acid substrates. Cif can thus target key host immune signals, exacerbating the damage caused by opportunistic pathogens such as P. aeruginosa.
AB - Pseudomonas aeruginosa secretes an epoxide hydrolase with catalytic activity that triggers degradation of the cystic fibrosis transmembrane conductance regulator (CFTR) and perturbs other host defense networks. Targets of this CFTR inhibitory factor (Cif) are largely unknown, but include an epoxy-fatty acid. In this class of signaling molecules, chirality can be an important determinant of physiological output and potency. Here we explore the active-site chemistry of this two-step α/β-hydrolase and its implications for an emerging class of virulence enzymes. In combination with hydrolysis data, crystal structures of 15 trapped hydroxyalkyl-enzyme intermediates reveal the stereochemical basis of Cif's substrate specificity, as well as its regioisomeric and enantiomeric preferences. The structures also reveal distinct sets of conformational changes that enable the active site to expand dramatically in two directions, accommodating a surprising array of potential physiological epoxide targets. These new substrates may contribute to Cif's diverse effects in vivo, and thus to the success of P. aeruginosa and other pathogens during infection. Hvorecny et al. crystallized covalent intermediates of the epoxide hydrolase virulence factor Cif. The structures collectively illuminate Cif's stereospecificity and uncover a new set of fatty acid substrates. Cif can thus target key host immune signals, exacerbating the damage caused by opportunistic pathogens such as P. aeruginosa.
KW - Enzyme stereospecificity
KW - Epoxide hydrolase
KW - Epoxy-fatty acids
KW - Hydroxyalkyl-enzyme intermediate
KW - Pseudomonas aeruginosa
KW - Structure-function relationships
KW - Virulence factor
KW - X-ray crystallography
UR - http://www.scopus.com/inward/record.url?scp=85017104673&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85017104673&partnerID=8YFLogxK
U2 - 10.1016/j.str.2017.03.002
DO - 10.1016/j.str.2017.03.002
M3 - Article
AN - SCOPUS:85017104673
JO - Structure with Folding & design
JF - Structure with Folding & design
SN - 0969-2126
ER -