The Cho lab publishes a research article in Science Advances

Soluble methane monooxygenase in methanotrophs converts methane to methanol under ambient conditions. The maximum catalytic activity of hydroxylase (MMOH) is achieved through the interplay of its regulatory protein (MMOB) and reductase. An additional auxiliary protein, MMOD, functions as an inhibitor of MMOH; however, its inhibitory mechanism remains unknown. Researchers in the laboratory of Uhn-Soo Cho and their collaborators at Chonbuk National University in the Republic of Korea report the 2.6 Å crystal structure of the MMOH-MMOD complex from Methylosinus sporium. The structure illustrates that the inhibitory protein MMOD associates with the canyon region of MMOH where the regulatory protein MMOB also binds. Although MMOD and MMOB recognize the same binding site, each binding component triggers different conformational changes in MMOH, which then respectively lead to the inhibition and activation of MMOH.