Cloning and characterization of chalcone synthase from the moss, Physcomitrella patens

• Published in: Phytochemistry (Oxford) 2006-12, Vol.67 (23), p.2531-2540
• Main Authors: Jiang, Chenguang, Schommer, Clark K., Kim, Sun Young, Suh, Dae-Yeon
• Format: Article
• Language: English
• Subjects: active sites; Acyltransferases - genetics; Acyltransferases - metabolism; Amino Acid Sequence; amino acid sequences; Biological and medical sciences; biosynthesis; Bryopsida - enzymology; Chalcone synthase; Chalcones - biosynthesis; Chalcones - chemistry; Cloning, Molecular; complementary DNA; conserved sequences; enzyme activity; Enzyme evolution; enzyme kinetics; expressed sequence tags; flavonoids; Funariaceae; Fundamental and applied biological sciences. Psychology; gene expression; Metabolism; molecular sequence data; Molecular Structure; Moss; mosses and liverworts; Multigene family; naringenin-chalcone synthase; Phylogeny; Physcomitrella patens; Plant physiology and development; recombinant fusion proteins; sequence analysis; Storage and secretion, pigments, phytochrome
• ISSN: 0031-9422; 1873-3700
• DOI: 10.1016/j.phytochem.2006.09.030

A gene encoding a chalcone synthase from the moss, Physcomitrella patens was cloned and the recombinant protein characterized. Its enzymatic properties were similar to those of higher plant CHSs. Phylogenetic analysis placed the moss CHS at the base of the plant CHS clade. Genomic sequence analysis revealed the presence of a CHS multigene family in the moss. Since the early evolution of land plants from primitive green algae, flavonoids have played an important role as UV protective pigments in plants. Flavonoids occur in liverworts and mosses, and the first committed step in the flavonoid biosynthesis is catalyzed by chalcone synthase (CHS). Although higher plant CHSs have been extensively studied, little information is available on the enzymes from bryophytes. Here we report the cloning and characterization of CHS from the moss, Physcomitrella patens. Taking advantage of the available P. patens EST sequences, a CHS (PpCHS) was cloned from the gametophores of P. patens, and heterologously expressed in Escherichia coli. PpCHS exhibited similar kinetic properties and substrate preference profile to those of higher plant CHS. p-Coumaroyl-CoA was the most preferred substrate, suggesting that PpCHS is a naringenin chalcone producing CHS. Consistent with the evolutionary position of the moss, phylogenetic analysis placed PpCHS at the base of the plant CHS clade, next to the microorganism CHS-like gene products. Therefore, PpCHS likely represents a modern day version of one of the oldest CHSs that appeared on earth. Further, sequence analysis of the P. patens EST and genome databases revealed the presence of a CHS multigene family in the moss as well as the 3′-end heterogeneity of a CHS gene. Of the 19 putative CHS genes, 10 genes are expressed and have corresponding ESTs in the databases. A possibility of the functional divergence of the multiple CHS genes in the moss is discussed.