Figure 7.

Neighbor-joining tree for deduced amino acid sequences of plant LCYb and LCYe (7, 9, 18) and of the related plant enzymes capsanthin–capsorubin synthase (21) and neoxanthin synthase (NSY; refs. 22, 23). Reactions catalyzed by the various enzymes are illustrated below the tree. A lycopene β-cyclase from the cyanobacterium Synechococcus PCC7942 (14) was used as the outgroup. Branch lengths are drawn to scale. Bootstrap values greater than 50% (for 10,000 replicates with a seed value of 111) are indicated. The analysis encompassed 398 positions, beginning with the initiating Met of the Synechococcus cyclase, and excluded those positions with gaps in the alignment. The amino acid sequence alignment and GenBank accession nos. for the nucleotide sequences are included in supplemental data (www.pnas.org). The method of Saitou and Nei (24) was used to construct the tree. Distances were corrected for multiple substitutions (25).