Fig. 4.

Sequence and structure of AsCYP51H10. (A) Alignment of selected regions of 36 representative CYP51 sequences from diverse organisms. The predicted substrate recognition sites (SRS) (16) are framed. Completely conserved amino acids are shown on a black background and those that are conserved in all except AsCYP51H10 are shown on a gray background. Mutations in sad2 mutants in these regions are shown (mutant number preceded by “#”; changes marked with black dots). Residues that line the active site cavity are indicated by triangles. The filled triangles denote the subset of these that are likely to be key determinants in modulating the size and shape of the cavity in AsCYP51H10. (B) Modeling of the active site cavity of AsCYP51H10 (Bottom) and the oat sterol 14α-demethylase AsCYP51G1 (Middle) based on the Mycobacterium tuberculosis MtCYP51B1 crystal structure (Top). (C) Phylogenetic analysis of CYP51 amino acid sequences. The numbers indicate the percentage of bootstrap replicates (out of 1,000) in which the given branching was observed. Accession nos. for the sequences used in alignments, modeling, and phylogenetic analysis are given in Table 2.