Conserved domain analysis of BmoA and BmoB from C. salexigens DSM 3043. (A) Identification of a NADH-binding domain and a plant-type [2Fe-2S] binding domain in the BmoB by amino acid sequence alignment with those of the flavin reductase components in the Rieske nonheme iron oxygenase (RO) class IA, as classified by Batie et al. (44). (B) Identification of a flavin-binding domain in the BmoB by amino acid sequence alignment with those of the flavin reductases in the RO class IB, as classified by Batie et al. (44). (C) Identification of a Rieske [2Fe-2S] domain and a nonheme Fe(II) domain in the BmoA by amino acid sequence alignment with those of the members in the RO family. Numbers represent the positions of the residues in the complete amino acid sequence of the following proteins (accession number): BmoB (499825574), a GB monooxygenase reductase component from C. salexigens DSM 3043; TsaB (AAC44805), a toluene sulfonate methyl-monooxygenase reductase component from Comamonas testosteroni T-2; VanB (O05617), a vanillate O-demethylase oxidoreductase from Pseudomonas sp. strain HR199; Pht2 (Q05182), a phthalate 4,5-dioxygenase reductase subunit from P. putida NMH102-2; CbaB (Q44257), a 3-chlorobenzoate-3,4-dioxygenase reductase subunit from Alcaligenes sp. strain BR60; PobB (Q52186), a phenoxybenzoate dioxygenase ferredoxin reductase from Pseudomonas pseudoalcaligenes POB310; AntC (AAC34815), an anthranilate dioxygenase reductase from Acinetobacter sp. strain ADP1; BenC (BAB70700), a benzoate 1,2-dioxygenase reductase from Rhodococcus sp. strain RHA1; CbdC (CAA55683), a 2-halobenzoate 1,2-dioxygenase reductase from Pseudomonas cepacia 2CBS; OxoR (CAA73201), a 2-oxo-1,2-dihyroquinoline 8-monooxygenase reductase from P. putida 86; BmoA (759867680), the terminal oxygenase component of GB monooxygenase from C. salexigens DSM 3043; GbcA (15600603), the predicted component of GB dioxygenase from P. aeruginosa PAO1; Stc2 (AAK65058), a stachydrine demethylase from S. meliloti 1021; CntA (EEX03955), the terminal oxygenase component of carnitine oxygenase from A. baumannii ATCC 19606; and OxyBAC (WP_068587002), benzalkonium chloride oxygenase from Pseudomonas sp. BIOMIG1. The amino acid residues conserved in the domains are indicated by asterisks (*), while identical amino acids residues in the aligned sequences are shown in black.