Intrinsic disorder in the regulatory N-terminal domain of diacylglycerol acyltransferase 1 from Brassica napus

April 9, 2019

Title

Intrinsic disorder in the regulatory N-terminal domain of diacylglycerol acyltransferase 1 from Brassica napus

Author

Rashmi Panigrahi, Tsutomu Matsui, Andrew H. Song, Kristian Mark P. Caldo, Howard S. Young, Randall J. Weselake, M. Joanne Lemieux

Year

2018

Journal

Scientific Reports

Abstract

Proteins with multifunctional regulatory domains often demonstrate structural plasticity or protein disorder, allowing the binding of multiple regulatory factors and post-translational modifications. While the importance of protein disorder is clear, it also poses a challenge for in vitro characterization. Here, we report protein intrinsic disorder in a plant molecular system, which despite its prevalence is less studied. We present a detailed biophysical characterization of the entire cytoplasmic N-terminal domain of Brassica napus diacylglycerol acyltransferase, (DGAT1), which includes an inhibitory module and allosteric binding sites. Our results demonstrate that the monomeric N-terminal domain can be stabilized for biophysical characterization and is largely intrinsically disordered in solution. This domain interacts with allosteric modulators of DGAT1, CoA and oleoyl-CoA, at micromolar concentrations. While solution scattering studies indicate conformational heterogeneity in the N-terminal domain of DGAT1, there is a small gain of secondary structure induced by ligand binding.

Instrument

J-810

Keywords

Circular dichroism, Secondary structure, Protein folding, Ligand binding, Biochemistry