Work

Solution structure and assembly of β-amylase2 from Arabidopsis thaliana

Year: 2019

Type: preprint

Abstract: Starch is a key energy storage molecule in plants that requires controlled synthesis and breakdown for effective plant growth. β-amylases (BAMs) hydrolyze starch into maltose to help meet the metabolic needs of the plant. In the model plant, Arabidopsis thaliana , there are nine BAMs which have apparently distinct functional and domain structures, although the functions of only a few of the BAMs are known and there are no 3-D structures of BAMs from this organism. Recently, AtBAM2 was proposed to form a tetramer based on chromatography and activity assays of mutants, however there was no direct observation of this tetramer. We collected small-angle X-ray scattering data on AtBAM2 and N-terminal mutants to describe the structure and assembly of the tetramer. Comparison of the scattering of the AtBAM2 tetramer to data collected using the sweet potato ( Ipomoea batatas ) BAM5, which is also reported to form a tetramer, showed there were differences in the overall assembly. Analysis of N-terminal truncations of AtBAM2 identified a loop sequence found only in BAM2 orthologs that appears to be critical for AtBAM2 tetramer assembly as well as activity.

Source: bioRxiv (Cold Spring Harbor Laboratory)

DOI: 10.1101/751602

Authors: Nithesh P. Chandrasekharan, Claire M. Ravenburg, Ian R. Roy, Jonathan D. Monroe, Christopher E. Berndsen

Institution: James Madison University

Language: English

Topic: Enzyme Structure and Function

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funders: National Science Foundation, Thomas F. and Kate Miller Jeffress Memorial Trust, Division of Chemistry, Lawrence Berkeley National Laboratory

Awards: G2452903922, REU Site: A Regional Summer Research Program Integrating Deaf and Hearing Participants in Chemistry Research, RUI:MCB: Glutathionylation of beta-amylase3 in Arabidopsis thaliana