Department of Biotechnology
inStem (Institute for Stem Cell Science and Regenerative Medicine)

Comparison of CryoEM and X-ray structures of dimethylformamidase.

Publication Type

Journal Article

Date of Publication

March 1, 2021

Journal

Progress in biophysics and molecular biology

Volume/Issue

160

ISSN

1873-1732

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.

Alternate Journal

Prog Biophys Mol Biol

PubMed ID

32735943

Authors

Kutti R Vinothkumar
Chetan Kumar Arya
Gurunath Ramanathan
Ramaswamy Subramanian

Keywords

Signal Transduction
Crystallography, X-Ray
Protein Conformation
Cryoelectron Microscopy
Water
Amidohydrolases
Protein Multimerization