A determinant of the number of ɛ-rings added to lycopene by
Arabidopsis and lettuce lycopene ɛ-cyclases was mapped
to a 6-aa region defined by the residues ALIVQF in the
Arabidopsis ɛ-cyclase and SHIVLM in the lettuce
ɛ-cyclase (see Figs. 4 and 5). Deduced amino acid sequences of
lycopene mono-ɛ-cyclases from tomato (9), marigold (18), and potato
(this work) are also displayed for this region. Similarly conserved
residues are shown in black text on a gray background. Three amino acid
residues in the lettuce bi-ɛ-cyclase that differ significantly from
those in the known mono-ɛ-cyclases are in white text on a black
background. Sequences of an Arabidopsis LCYb (a
bicyclase) and an Adonis LCYe of mixed function are
displayed below the lettuce LCYe with two residues of interest shown in
white text on a black background. Similarity was defined according to
the blosum 45 scoring matrix (19): DE,
NH, ST, QKR, FYW, LIVM. GenBank accession nos.: Adonis
LCYe1, AF321535; Arabidopsis
LCYb, U50739; Arabidopsis
LCYe, U50738; lettuce LCYe, AF321538;
marigold LCYe, AF251016; potato LCYe,
AF321537; tomato LCYe, Y14387.