title: Didehydrophenylalanine, an abundant modification in the beta subunit of plant polygalacturonases.
abstract: The structure and the activity of proteins are often regulated by transient or stable post- translational modifications (PTM). Different from well-known, abundant modifications such as phosphorylation and glycosylation some modifications are limited to one or a few proteins across a broad range of related species. Although few examples of the latter type are known, the evolutionary conservation of these modifications and the enzymes responsible for their synthesis suggest an important physiological role. Here, the first observation of a new, fold-directing PTM is described. During the analysis of alfalfa cell wall proteins a -2Da mass shift was observed on phenylalanine residues in the repeated tetrapeptide FxxY of the beta-subunit of polygalacturonase. This modular protein is known to be involved in developmental and stress-responsive processes. The presence of this modification was confirmed using in-house and external datasets acquired by different commonly used techniques in proteome studies. Based on these analyses it was found that all identified phenylalanine residues in the sequence FxxY of this protein were modified to α,β-didehydro-Phe (ΔPhe). Besides showing the reproducible identification of ΔPhe in different species arguments that substantiate the fold-determining role of ΔPhe are given.
authors.affiliation: Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.
authors.forename: Kjell
authors.identifier: http://orcid.org/0000-0003-2071-3510
authors.initials: K
authors.lastname: Sergeant
authors.affiliation: Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.|Université catholique de Louvain, Earth and Life Institute Agronomy, Groupe de Recherche en Physiologie Végétale Louvain-la-Neuve, Belgium.
authors.forename: Bruno
authors.initials: B
authors.lastname: Printz
authors.affiliation: Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.|University of Hasselt, Centre for Environmental Sciences, Environmental Biology, Diepenbeek, Belgium.
authors.forename: Annelie
authors.initials: A
authors.lastname: Gutsch
authors.affiliation: Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.|Université catholique de Louvain, Earth and Life Institute Agronomy, Groupe de Recherche en Physiologie Végétale Louvain-la-Neuve, Belgium.
authors.forename: Marc
authors.initials: M
authors.lastname: Behr
authors.affiliation: Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.
authors.forename: Jenny
authors.initials: J
authors.lastname: Renaut
authors.affiliation: Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) department, Esch-sur-Alzette, Luxembourg.
authors.forename: Jean-Francois
authors.initials: JF
authors.lastname: Hausman
mesh_terms: D000595:Amino Acid Sequence; D002473:Cell Wall / Q000201:enzymology*; D006031:Glycosylation; D000455:Medicago sativa / Q000201:enzymology*; D010649:Phenylalanine / Q000031:analogs & derivatives* / Q000737:chemistry; D010766:Phosphorylation; D011096:Polygalacturonase / Q000737:chemistry* / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D020543:Proteome; D040901:Proteomics
chemical_list: D020543:Proteome; D010649:Phenylalanine; C018632:phenyldehydroalanine; D011096:Polygalacturonase