3-Hydroxybenzoate 6-Hydroxylase from Rhodococcus jostii RHA1 Contains a Phosphatidylinositol Cofactor

Stefania Montersino, Evelien te Poele, Roberto Orru, Adrie H. Westphal, Arjan Barendregt, Albert J. R. Heck, Robert van der Geize, Lubbert Dijkhuizen, Andrea Mattevi, Willem J. H. van Berkel
  • Frontiers in Microbiology, June 2017, Frontiers Media SA
  • DOI: 10.3389/fmicb.2017.01110

3-Hydroxybenzoate 6-Hydroxylase from Rhodococcus jostii Contains a Phosphatidylinositol Cofactor

What is it about?

3-Hydroxybenzoate 6-hydroxylase (3HB6H, EC 1.13.14.26) is a FAD-dependent monooxygenase involved in the catabolism of aromatic compounds in soil microorganisms. 3HB6H is unique among flavoprotein hydroxylases in that it harbors a phospholipid ligand. Here, we produced Rj3HB6H in the host R. jostii RHA#2 by employing a newly developed actinomycete expression system. Biochemical and biophysical analysis revealed that Rj3HB6H contains phosphatidylinositol, a specific constituent of actinomycete membranes. Native mass spectrometry suggests that the lipid cofactor stabilizes monomer-monomer contact.

Why is it important?

Understanding the function of the phospholipid ligand of 3HB6H is important for getting a better understanding of the structure-function relationship of flavoprotein mono-oxygenases and will facilitate their biocatalytic application for the production of high-value compounds.

Perspectives

Professor Willem J.H. van Berkel
Wageningen University

More insight into the evolutionary relationship and catalytic properties of flavin-dependent aromatic hydroxylases is of eminent importance for understanding enzyme dynamics.

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http://dx.doi.org/10.3389/fmicb.2017.01110

The following have contributed to this page: Professor Lubbert Dijkhuizen and Professor Willem J.H. van Berkel