Pterocarpan synthase (PTS) structures suggest a common quinone methide-stabilizing function in dirigent proteins and proteins with dirigent-like domains.
J Biol Chem
; 295(33): 11584-11601, 2020 08 14.
Article
em En
| MEDLINE
| ID: mdl-32565424
ABSTRACT
The biochemical activities of dirigent proteins (DPs) give rise to distinct complex classes of plant phenolics. DPs apparently began to emerge during the aquatic-to-land transition, with phylogenetic analyses revealing the presence of numerous DP subfamilies in the plant kingdom. The vast majority (>95%) of DPs in these large multigene families still await discovery of their biochemical functions. Here, we elucidated the 3D structures of two pterocarpan-forming proteins with dirigent-like domains. Both proteins stereospecifically convert distinct diastereomeric chiral isoflavonoid precursors to the chiral pterocarpans, (-)- and (+)-medicarpin, respectively. Their 3D structures enabled comparisons with stereoselective lignan- and aromatic terpenoid-forming DP orthologs. Each protein provides entry into diverse plant natural products classes, and our experiments suggest a common biochemical mechanism in binding and stabilizing distinct plant phenol-derived mono- and bis-quinone methide intermediates during different C-C and C-O bond-forming processes. These observations provide key insights into both their appearance and functional diversification of DPs during land plant evolution/adaptation. The proposed biochemical mechanisms based on our findings provide important clues to how additional physiological roles for DPs and proteins harboring dirigent-like domains can now be rationally and systematically identified.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas de Plantas
/
Pisum sativum
/
Pterocarpanos
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Glycyrrhiza
/
Ligases
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Estados Unidos