Methanobactin: A Novel Copper-Binding Compound Produced by Methanotrophs

Aerobic methanotrophs are a novel group of microorganisms that play a critical role in the global carbon cycle. Expression and activity of a key enzyme in the metabolism in these microbes, the methane monooxygenase, is controlled by the availability of copper. To sequester copper, some methanotrophs produce a ribosomally synthesized post-translationally modified polypeptide called methanobactin. This peptide, or chalkophore, has unique features, with all known forms being small (<1300 Da) with two heterocyclic rings with associated thioamide groups that bind copper quite strongly. Here we provide an overview of the known diversity of methanobactins, describe the genetics underlying the methanobactin biosynthesis, the variety of functions methanobactin has been observed to have, as well as various environmental, industrial and medical applications of methanobactin.