Quaternary Structure, Salt Sensitivity, and Allosteric Regulation of β-AMYLASE2 From Arabidopsis thaliana

Frontiers in Plant Science
Jonathan D MonroeAmanda R Storm

Abstract

The β-amylase family in Arabidopsis thaliana has nine members, four of which are both plastid-localized and, based on active-site sequence conservation, potentially capable of hydrolyzing starch to maltose. We recently reported that one of these enzymes, BAM2, is catalytically active in the presence of physiological levels of KCl, exhibits sigmoidal kinetics with a Hill coefficient of over 3, is tetrameric, has a putative secondary binding site (SBS) for starch, and is highly co-expressed with other starch metabolizing enzymes. Here we generated a tetrameric homology model of Arabidopsis BAM2 that is a dimer of dimers in which the putative SBSs of two subunits form a deep groove between the subunits. To validate this model and identify key residues, we generated a series of mutations and characterized the purified proteins. (1) Three point mutations in the putative subunit interfaces disrupted tetramerization; two that interfered with the formation of the starch-binding groove were largely inactive, whereas a third mutation prevented pairs of dimers from forming and was active. (2) The model revealed that a 30-residue N-terminal acidic region, not found in other BAMs, appears to form part of the putative starch-binding groove. ...Continue Reading

References

Jan 29, 2000·The Plant Journal : for Cell and Molecular Biology·N T LaoT A Kavanagh
Apr 7, 2000·The Journal of Biological Chemistry·G ValentiniA Mattevi
Jun 6, 2002·The Plant Journal : for Cell and Molecular Biology·Andreas ScheidigJens Kossmann
Jul 26, 1963·Biochemical and Biophysical Research Communications·J A THOMAR BALDWIN
Nov 4, 2005·The Journal of Biological Chemistry·Enrico Di Cera
Apr 19, 2008·The Plant Journal : for Cell and Molecular Biology·Mahdi HejaziGerhard Ritte
Mar 3, 2010·Annual Review of Plant Biology·Samuel C ZeemanAlison M Smith
Jun 30, 2011·Critical Reviews in Biotechnology·Sven CuyversChristophe M Courtin
Jun 19, 2012·Accounts of Chemical Research·Juan Luis AsensioJesús Jiménez-Barbero
Aug 27, 2014·Journal of Pharmacological and Toxicological Methods·Sudhindra R Gadagkar, Gerald B Call
Dec 3, 2014·Cell Calcium·Giovanni FinazziDaphné Seigneurin-Berny
Dec 31, 2014·Nature Methods·Jianyi YangYang Zhang
Jan 18, 2016·Current Biology : CB·Daniel HorrerDiana Santelia
Oct 27, 2017·Plant Physiology·Jonathan D MonroeAmanda R Storm

❮ Previous
Next ❯

Citations

Apr 8, 2020·Acta Crystallographica. Section D, Structural Biology·Nithesh P ChandrasekharanChristopher E Berndsen

❮ Previous
Next ❯

Methods Mentioned

BETA
Light Scattering
PCR
Protein Assay

Software Mentioned

YASARA
Excel Solver
TASSER
ExPASy Server

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.