OSC superfamily

The deduced amino acid sequence of AsbASl contains the conserved DCTAE motif implicated in substrate binding in OSCs,37 and also four conserved QW motifs that are characteristic for the OSC superfamily.38 Remarkably, AsbASl is clearly distinct from the other cloned PAS enzymes that have been characterized to date from other plant species, and is more closely related to lanosterol synthases from animals and fungi than to triterpenoid synthases or cycloartenol synthases from plants (Fig. 5.3).35 There are substantial mechanistic differences in the processes of... 

OSCs that have been functionally characterised by expression in yeast are hsted in Table 2, and the relatedness between the amino acid sequences of these enzymes is illustrated in Fig. 3. The conserved features of this OSC superfamily and the differences between them that may confer product specificity are considered below. 

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