The "Methylophilus methylotrophus" trimethylamine dehydrogenase () TIM barrel is an example of a complete domain insertion. Here, a Rossmann fold domain is inserted at the C-terminal end of the TIM-barrel. Trimethylamine dehydrogenase catalyzes the conversion of trimethylamine to formaldehyde. This reaction requires both a reduced 6-S-cysteinyl Flavin mononucleotide (FMN) cofactor and a reduced iron-sulphur (center. FMN is covalently bound within the C-terminal region of the β-barrel. The [4Fe-4S+ center is too large to be accommodated within the TIM barrel, and is instead placed in close proximity, 7 Å away, at the interface between the TIM barrel and Rossmann fold domains.