Figure 8.

Alignment of S. bicolor and O. sativa Sequences Exhibiting ARS Activity.

The sequences for S. bicolor ARS1 and ARS2 and the ARSs encoded by O. sativa LOC_Os05g12180, LOC_Os10g08620, and LOC_Os10g07040 were aligned with M. sativa CHS2, G. hybrida 2-PS, S. bicolor CHS2, S. bicolor 0_1848, and O. sativa CHS1 using ClustalW. Residues associated with PKS functional diversity, catalysis (catalytic triad), and CoA binding are indicated based on previous crystallography studies (Ferrer et al., 1999; Jez et al., 2000) and by computational homology modeling of ARS1 and ARS2. Numbering shown above the catalytic triad positions, as well as several key residues potentially contributing to active site architecture, is based on the M. sativa CHS2 sequence. Also indicated by boxes are atypical residues identified within the 0_1848-encoded polypeptide that could account for the lack of enzymatic activity observed in recombinant enzyme studies.