(A) Amino acid sequence alignment between the maize STC1
protein and sesquiterpene cyclases from oil palm (GenBank accession no.
AAC31570), Gossypium arboreum [δ-cadinene synthase
(δ-cadin), Swissprot Q39760], and Nicotiana tabaccum
[5-epiaristolochene synthase (5EAS), Swissprot Q40577]. The sequences
were aligned with the GCG program PILEUP. A residue
that is highly conserved appears in bold. Gaps are represented by dots.
Amino acids corresponding to the conserved DDXXD motif are underlined.
(B) stc1 gene structure. Exons are
represented as open boxes, the numbers referring to the approximate
number of amino acids in each exon. The 5′ and 3′ untranslated regions
(UTRs) are shown as double lines, and the Ac6087
insertion is shown as an inverted triangle in the 5′ UTR. The
stc1 genomic sequence has been deposited in GenBank
(accession no. AF296123).