Domain structure of CYP97 from algae. A partial protein sequence (position: 272–926) has been selected for domain structure analysis. The red shades indicated conserved amino acid residues in CYP97A and CYP97C homologs from green algae. The green shades indicated conserved amino acid residues in all CYP97B homologs from all algae. The P450s active site components were found in the amino acid sequences of all CYP97A/B/C, including I-helix involved in oxygen binding (CD6 in CYP97B and CD5 in CYP97A and CYP97C), ERR triad (CD7 in CYP97A/B/C) involved in locking the heme pockets into position and to assure stabilization of the conserved core structure, and CD10 involved in heme binding and a conserved cysteine (the circle with blue color). The abbreviations used are: Chl-C, CYP97C from Chlorophyta C. reinhardtii, V. carteri, M. sp. RCC299, O. RCC809, and Cercozoa B. natans CCMP2755; Chl-A, CYP97A from Chlorophyta C. reinhardtii, V. carteri, M. sp. RCC299, and O. RCC809; Chl-B, CYP97B from Chlorophyta M. sp. RCC299, O. RCC809, and V. carteri; Cry-B, CYP97B from Cryptophyta G. theta; Bac-B, CYP97B from Bacillariophyta T. pseudonana, P. tricornutum, F. cylindrus, and Stramenopiles A. anophagefferens; Hap-B, CYP97B from E. huxleyi. The information of BCH genes from algae is as in Table 1.