TitleComparison of CryoEM and X-ray structures of dimethylformamidase.
Publication TypeJournal Article
Year of Publication2020
AuthorsVinothkumar KR, Arya CKumar, Ramanathan G, Subramanian R
JournalProg Biophys Mol Biol
Date Published2020 Jul 28
ISSN1873-1732
Abstract

Dimethylformamidase (DMFase) catalyzes the hydrolysis of dimethylformamide, an industrial solvent, introduced into the environment by humans. Recently, we determined the structures of dimethylformamidase by electron cryo microscopy and X-ray crystallography revealing a tetrameric enzyme with a mononuclear iron at the active site. DMFase from Paracoccus sp. isolated from a waste water treatment plant around the city of Kanpur in India shows maximal activity at 54 °C and is halotolerant. The structures determined by both techniques are mostly identical and the largest difference is in a loop near the active site. This loop could play a role in co-operativity between the monomers. A number of non-protein densities are observed in the EM map, which are modelled as water molecules. Comparison of the structures determined by the two methods reveals conserved water molecules that could play a structural role. The higher stability, unusual active site and negligible activity at low temperature makes this a very good model to study enzyme mechanism by cryoEM.

DOI10.1016/j.pbiomolbio.2020.06.008
Alternate JournalProg Biophys Mol Biol
PubMed ID32735943