Identification and functional analysis of bifunctional ent-kaurene synthase from the moss Physcomitrella patens

FEBS Lett. 2006 Nov 13;580(26):6175-81. doi: 10.1016/j.febslet.2006.10.018. Epub 2006 Oct 17.

Abstract

ent-Kaurene is the key intermediate in biosynthesis of gibberellins (GAs), plant hormones. In higher plants, ent-kaurene is synthesized successively by copalyl diphosphate synthase (CPS) and ent-kaurene synthase (KS) from geranylgeranyl diphosphate (GGDP). On the other hand, fungal ent-kaurene synthases are bifunctional cyclases with both CPS and KS activity in a single polypeptide. The moss Physcomitrella patens is a model organism for the study of genetics and development in an early land plant. We identified ent-kaurene synthase (PpCPS/KS) from P. patens and analyzed its function. PpCPS/KS cDNA encodes a 101-kDa polypeptide, and shows high similarity with CPSs and abietadiene synthase from higher plants. PpCPS/KS is a bifunctional cyclase and, like fungal CPS/KS, directly synthesizes the ent-kaurene skeleton from GGDP. PpCPS/KS has two aspartate-rich DVDD and DDYFD motifs observed in CPS and KS, respectively. The mutational analysis of two conserved motifs in PpCPS/KS indicated that the DVDD motif is responsible for CPS activity (GGDP to CDP) and the DDYFD motif for KS activity (CDP to ent-kaurene and ent-16alpha-hydroxykaurene).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkyl and Aryl Transferases / genetics*
  • Alkyl and Aryl Transferases / physiology*
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Bryophyta / enzymology*
  • Mutagenesis, Site-Directed
  • Phylogeny
  • Plant Proteins
  • Sequence Alignment

Substances

  • Plant Proteins
  • Alkyl and Aryl Transferases
  • ent-kaurene synthetase A
  • ent-kaurene synthetase B