Cryo-EM structure of the MMOH-MMOR complex
EMSL Project ID
51187
Abstract
Methane to methanol conversion is critical for environmental health, reducing greenhouse gas, and utilizing the natural gas as an alternative energy source. Methanotrophic bacteria utilize the methane (CH4) as a sole source of carbon and energy by oxidizing and breaking the highly stable C-H bond. This unique reaction can be achieved via the enzyme complex called methane monooxygenase (MMO). Soluble methane monooxygenase (sMMO) is a multi-component protein complex comprising a 245-kDa (???)2 hydroxylase MMOH, a 16-kDa regulatory protein MMOB, a 38-kDa electron-transfer reductase MMOR, and 12-kDa potential MMO inhibitory subunit (MMOD). Since the maximum catalytic activity of sMMO is only achieved via the interplay of MMOH with three auxiliary subunits, structural elucidation is a key to understand its chemistry and to develop bio-mimetic catalysts.
We have recently determined the crystal structures of both MMOH bound to the activator (MMOB) and the inhibitor (MMOD), and structures revealed the key underlying molecular mechanisms.
In this proposed research, we aim to determine the EM structure of MMOH bound to the reductase (MMOR). Our preliminary data indicates that MMOH behaves well under the microscope. Since the crystal and NMR structures of both MMOH and MMOR are available, we can fit these known structures even in the intermediate resolution (~5Å). The structure will elucidate the atomic details of the mechanism by which MMOR shuttles electrons from NADH to MMOH. Additionally this work can suggest several potential conformational rearrangements that might occur in MMOH or MMOR during the reduction.
Project Details
Start Date
2020-02-15
End Date
2020-08-15
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members