2014 journal article

Computational and genetic evidence that different structural conformations of a non-catalytic region affect the function of plant cellulose synthase

JOURNAL OF EXPERIMENTAL BOTANY, 65(22), 6645–6653.

co-author countries: United States of America 🇺🇸
author keywords: Cellulose biosynthesis; CESA; genetic complementation; protein structural modelling; rsw1 mutant; transmembrane helix
MeSH headings : Amino Acid Sequence; Arabidopsis / enzymology; Arabidopsis / genetics; Arabidopsis Proteins / chemistry; Arabidopsis Proteins / genetics; Arabidopsis Proteins / metabolism; Biocatalysis; Computational Biology; Glucosyltransferases / chemistry; Glucosyltransferases / genetics; Glucosyltransferases / metabolism; Molecular Sequence Data; Mutant Proteins / metabolism; Mutation; Phenotype; Protein Structure, Secondary; Recombinant Fusion Proteins / metabolism; Sequence Alignment; Structure-Activity Relationship
Source: Web Of Science
Added: August 6, 2018

The β-1,4-glucan chains comprising cellulose are synthesized by cellulose synthases in the plasma membranes of diverse organisms including bacteria and plants. Understanding structure–function relationships in the plant enzymes involved in cellulose synthesis (CESAs) is important because cellulose is the most abundant component in the plant cell wall, a key renewable biomaterial. Here, we explored the structure and function of the region encompassing transmembrane helices (TMHs) 5 and 6 in CESA using computational and genetic tools. Ab initio computational structure prediction revealed novel bi-modal structural conformations of the region between TMH5 and 6 that may affect CESA function. Here we present our computational findings on this region in three CESAs of Arabidopsis thaliana (AtCESA1, 3, and 6), the Atcesa3ixr1-2 mutant, and a novel missense mutation in AtCESA1. A newly engineered point mutation in AtCESA1 (Atcesa1F954L) that altered the structural conformation in silico resulted in a protein that was not fully functional in the temperature-sensitive Atcesa1rsw1-1 mutant at the restrictive temperature. The combination of computational and genetic results provides evidence that the ability of the TMH5–6 region to adopt specific structural conformations is important for CESA function.