Berberine bridge enzyme-like proteins: a multi-gene family from vascular plants

Bastian Daniel, Barbara Steiner, Tea Pavkov-Keller, Karl Gruber, Eric van der Graaff, Thomas Roitsch, Silvia Wallner, Peter Macheroux

Research output: Contribution to conference(Old data) Lecture or Presentation


Berberine bridge enzyme-like proteins: a multi-gene family from vascular plants

Bastian Daniel1, Barbara Steiner1, Silvia Wallner1, Karl Gruber2, Tea Pavkov-Keller2, 3, Eric van der Graaff4, Thomas Roitsch4 and Peter Macheroux1

1Institute of Biochemistry, Graz University of Technology, Petersgasse 12/2, 8010 Graz, Austria
2Institute of Molecular Biosciences, University of Graz, Humboldtstraße 50, 8010 Graz, Austria
3Austrian Centre of Industrial Biotechnology, Petersgasse 14, 8010 Graz, Austria
4Department of Plant and Environmental Sciences, Copenhagen University, Højbakkegård Allé 13, 2630 Taastrup, Denmark

Flavoproteins are a diverse protein class employing an isoalloxazine ring for catalysis in form of the flavin mononucleotide (FMN) or the flavin adenine dinucleotide (FAD). Among them is the berberine bridge enzyme-like (BBE-like) protein family (pfam 08031) named after the berberine bridge enzyme (EcBBE) from California poppy (Eschscholzia californica). BBE-like proteins form a multigene family in plants and the number of members varies from one in the moss Physcomitrella patens to 57 in the western poplar (Populus trichocarpa). Despite the frequent occurrence of these proteins their function is largely unknown. Therefore, we chose to investigate the gene encoding for BBE-like proteins from Arabidopsis thaliana to broaden our understanding of this protein family. Here we present the characterization of AtBBE-like protein 15 and a putative loss-of-function mutant of the respective gene.
AtBBE-like protein 15 and 13 were expressed heterologously and identified as monolignol oxidoreductases. They are localized in the plant cell wall and catalyse the oxidation of one of the major cell wall components, the monolignols, to the corresponding aldehydes. This suggests a role of BBE-like proteins in monolignol metabolism and lignin formation that was prior not recognized for this protein family. The structure of AtBBE-like protein 15 was elucidated by protein crystallography. The catalytic machinery can be divided into the active site and a substrate binding site. 14 out of 28 AtBBE-like proteins share the same active site while the substrate binding site of AtBBE-like protein 15 is restricted to a small set of proteins, a similar substrate scope and mechanism is anticipated for these enzymes. As the structural and biochemical characterization of AtBBE-like protein 15 and 13 indicates an involvement in lingnification we have initiated the characterization of the respective enzymes in planta.
Original languageGerman
Publication statusPublished - 14 Jun 2016
EventBotanisches Kolloquium - Karl Franzens Universität, Graz, Austria
Duration: 14 Jul 2015 → …


SeminarBotanisches Kolloquium
Period14/07/15 → …

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