Figure 1.

Conserved two-arginine residues in members of the family of FMN-containing flavoproteins that catalyze the oxidation of α-hydroxyacids. Only parts of the sequences are shown; those on the left containing the recently recognized catalytically important arginine residue, those on the right also containing the active site histidine residue. Abbreviations: LOX, lactate oxidase of Aerococcus viridans, (GenBank accession no. E02499); LMO, lactate monooxygenase from Mycobacterium smegmatis (J05402); GLO, glycolate oxidase from spinach, (J03492); b₂^′ flavocytochrome b₂ from Saccharomyces cerevisiae (X03215); MDH, mandelate dehydrogenase from Pseudomonas putida (J05293); LHO, long chain α-hydroxyacid oxidase from rat (X67156).