abstract:Methanobactin (mb) is a class of copper-binding and reducing chromophoric peptides initially identified in the methanotroph Methylococcus capsulatus Bath - and later in Methylosinus tricasporium OB3b - during the isolation of the membrane-associated or particulate methane monooxygenase (pMMO). It is thought to be secreted to the extracellular media to recruit copper, a critical component of methane monooxygenase, the first enzyme in the series that catalyzes the oxidation of methane into methanol.