5TNS

Crystal structure of the D129S mutant of the CFTR inhibitory factor Cif containing 1,2-Epoxycyclohexane

Summary for 5TNS

• Entry DOI: 10.2210/pdb5tns/pdb
• Related: 3KD2 4DMC 5TNJ
• Descriptor: CFTR inhibitory factor, (1R,6S)-7-oxabicyclo[4.1.0]heptane (3 entities in total)
• Functional Keywords: epoxide hydrolase, hydroxyalkyl-enzyme intermediate, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• Biological source: Pseudomonas aeruginosa (strain UCBPP-PA14)
• Total number of polymer chains: 4
• Total formula weight: 136644.91

Authors

Hvorecny, K.L.,Madden, D.R. (deposition date: 2016-10-14, release date: 2017-10-11, Last modification date: 2023-10-04)

Primary citation

Hvorecny, K.L.,Bahl, C.D.,Kitamura, S.,Lee, K.S.S.,Hammock, B.D.,Morisseau, C.,Madden, D.R.
Active-Site Flexibility and Substrate Specificity in a Bacterial Virulence Factor: Crystallographic Snapshots of an Epoxide Hydrolase.
Structure, 25:697-707.e4, 2017

PubMed 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.

PubMed: 28392259
DOI: 10.1016/j.str.2017.03.002

Experimental method

X-RAY DIFFRACTION (1.75 Å)