Sterigmatocystin 7-O-methyltransferase (OmtA) (OmtA)

Sterigmatocystin 7-O-methyltransferase, commonly referred to as O-methyltransferase A (OmtA), is a vital enzyme in the aflatoxin biosynthetic pathway of fungi such as Aspergillus flavus and Aspergillus parasiticus [1, 2]. It catalyzes the S-adenosyl-L-methionine (SAM)-dependent methylation of sterigmatocystin (ST) to form O-methylsterigmatocystin (OMST), a key penultimate step in the production of the potent hepatocarcinogen aflatoxin B1 [2, 14]. Due to the severe health impacts of aflatoxins, which include acute toxicosis and a high risk of hepatocellular carcinoma in humans, OmtA is considered a significant target for anti-aflatoxigenic intervention [1, 14]. Current research focuses on discovering small-molecule inhibitors like piperlonguminine and blasticidin S, and employing gene-silencing techniques like Host-Induced Gene Silencing (HIGS) to reduce toxin levels in crops [2, 4]. By targeting this enzymatic step, biotechnologists aim to block the synthesis of toxic metabolites while preserving the ecological niche of the fungus [2]. Safety and efficacy evaluations are crucial to ensure that inhibitors do not interfere with host methyltransferase systems or cause broader environmental damage [1, 12].

Other names

O-methyltransferase AOmt-AaflPSterigmatocystin methyltransferaseSterigmatocystin 7-O-methyltransferase

Inhibition of the enzymatic conversion of sterigmatocystin to O-methylsterigmatocystin in the aflatoxin biosynthetic pathway [1, 2].