A new principle of oligomerisation of plant DEG7 protease based on interactions of degenerated protease domains

Holger Schuhmann , Ulrike Mogg , Iwona Adamska (1)

1 Dept of Physiology and Plant Biochemistry

Deg/HtrA proteases are a large group of ATP-independent serine endoproteases found in almost every organism. Their usual domain arrangement comprises a trypsin type protease domain and one or more PDZ domains. All Deg/HtrA proteases form homo-oligomers with trimers as the basic unit, where the active protease domain mediates the interaction between individual monomers. Among the members of the Deg/HtrA protease family, the plant protease DEG7 is unique since it contains two protease domains (one active and one degenerated) and four PDZ domains. In this study, we investigate the oligomerisation behaviour of this unusual protease by yeast two-hybrid analysis in vivo and with recombinant protein in vitro. We show that DEG7 forms trimeric complexes, but in contrast to other known Deg/HtrA proteases it shows a new principle of oligomerisation, where trimerisation is based on the interactions between degenerated protease domains. We propose that during evolution a duplicated active protease domain degenerated and specialised on protein-protein interaction and complex formation.

Mots clés: Life Sciences

Holger Schuhmann, Ulrike Mogg, Iwona Adamska. A new principle of oligomerisation of plant DEG7 protease based on interactions of degenerated protease domains. Biochemical Journal, 2011, 435 (1), pp.167-174. ⟨10.1042/BJ20101613⟩. ⟨hal-00576991⟩