Deciphering the role of recurrent FAD-dependent enzymes in bacterial phosphonate catabolism

Erika Zangelmi; Francesca Ruffolo; Tamara Dinhof; Marco Gerdol; Marco Malatesta; Jason P Chin; Claudio Rivetti; Andrea Secchi; Katharina Pallitsch; Alessio Peracchi

doi:10.1016/j.isci.2023.108108

Deciphering the role of recurrent FAD-dependent enzymes in bacterial phosphonate catabolism

iScience. 2023 Oct 4;26(11):108108. doi: 10.1016/j.isci.2023.108108. eCollection 2023 Nov 17.

Authors

Affiliations

¹ Department of Chemistry, Life Sciences and Environmental Sustainability, University of Parma, 43124 Parma, Italy.
² Institute of Organic Chemistry, Faculty of Chemistry, University of Vienna, 1090 Vienna, Austria.
³ Vienna Doctoral School in Chemistry (DoSChem), University of Vienna, 1090 Vienna, Austria.
⁴ Department of Life Sciences, University of Trieste, Via Giorgieri 5, 34127 Trieste, Italy.
⁵ School of Biological Sciences and Institute for Global Food Security, Queen's University Belfast, 19 Chlorine Gardens, BT9 5DL Belfast, UK.

Abstract

Phosphonates-compounds containing a direct C-P bond-represent an important source of phosphorus in some environments. The most common natural phosphonate is 2-aminoethylphosphonate (AEP). Many bacteria can break AEP down through specialized "hydrolytic" pathways, which start with the conversion of AEP into phosphonoacetaldehyde (PAA), catalyzed by the transaminase PhnW. However, the substrate scope of these pathways is very narrow, as PhnW cannot process other common AEP-related phosphonates, notably N-methyl AEP (M₁AEP). Here, we describe a heterogeneous group of FAD-dependent oxidoreductases that efficiently oxidize M₁AEP to directly generate PAA, thus expanding the versatility and usefulness of the hydrolytic AEP degradation pathways. Furthermore, some of these enzymes can also efficiently oxidize plain AEP. By doing so, they surrogate the role of PhnW in organisms that do not possess the transaminase and create novel versions of the AEP degradation pathways in which PAA is generated solely by oxidative deamination.

Keywords: Bacteriology; Enzymology; Microbial metabolism.