Isolation and characterization of Aconitate hydratase 4 (Aco4) from soybean

Abstract

Aconitase catalyzes the reversible isomerization of two tricarboxylic acids, citrate and isocitrate, during the Krebs cycle. Five aconitase genes, namely, Aco1, Aco2, Aco3, Aco4, and Aco5, have been identified in soybean. Previously, Aco4 was mapped on chromosome 11. The purpose of this investigation was to isolate and sequence the candidate gene for Aco4. We mapped the Aco4 gene to a 148 kb region on chromosome 11 that contained 19 predicted genes. One of these, Glyma.11G080600, codes for aconitate hydratase. Sequencing of two isozyme variants (A-line and B-line) for Glyma.11G080600 revealed three synonymous and two non-synonymous substitutions. Perhaps, the two non-synonymous substitutions resulted in a variable isozyme pattern between the variants. Glyma.11G080600 contains a catalytic domain and a swivel domain that are known to catalyze isomerization of citrate to isocitrate and swiveling conformational change in the enzyme mechanism, respectively. Conservation of both the domains implies the role of Glyma.11G080600 in the interconversion of citrate and isocitrate. Glyma.11G080600 is expressed in most tissues, with maximum expression in leaves. Phylogenetic analysis of 25 genes from different species displayed three major clusters. Glyma.11G080600 (Aco4) and Glyma.01G162800, which are conserved in Glycine max (L.) Merr. and Glycine soja Siebold. & Zucc., may have common ancestry before G. max and G. soja split.

Transcriptomic and phosphoproteomic profiling and metabolite analyses reveal the mechanism of NaHCO3-induced organic acid secretion in grapevine roots

“…Collectively, the above results suggest that the OAA pathway is the main pathway for oxalate and acetate biosynthesis under alkali stress. However, notably, the glycolate/glyoxylate pathway might also be modified in grapevine roots under alkali stress, as indicated by the significant increase in the phosphorylation level of aconitate hydratase (aconitase), a key protein in the glycolate/glyoxylate pathway [30].…”

Soybean [Glycine max (L.) Merr.] agronomic performance, seed characteristics, and aconitase isozymes variability in response to environmental stimuli

“…1). Coleman et al (2016) also found that SNP substitutions in the exon of the Aco4 gene in two soybean cultivars resulted in amino acid changes and different protein sequences. The authors hypothesized that these differences could produce different protein structures and aconitase isozyme patterns.…”

“…Recent soybean studies identified aconitase isozymes allelic variation in homozygous cultivars exposed to environmental stimuli (Espinosa et al, 2015;Coleman et al, 2016 (Rouault and Klausner 1996;Sadka et al, 2000;Shlizerman et al, 2007).The Krebs cycle generates energy for organism's metabolic processes (Schnarrenberger and Martin, 2002). Aconitase is comprised of iron-sulfur cluster (3Fe-4S) in its inactive form and is activated through the binding of a fourth free iron to form 4Fe-4S cluster (Zhou and Ragan 1995;Gardner 1997;Shlizerman et al, 2007).…”

“…Recent studies identified aconitase isozymes allelic variation in soybean homozygous cultivars exposed to environmental stimuli (Espinosa et al, 2015;Coleman et al, 2016 (Rouault and Klausner 1996;Sadka et al, 2000;Shlizerman et al, 2007).…”

“…Five aconitase isozymes, namely Aco1, Aco2, Aco3, Aco4 and Aco5, have been identified in soybeans (Griffin and Palmer, 1987;Kiang and Bult 1991;Terol et al, 2010;Espinosa et al, 2015). Aco4 gene (Glyma.11g080600) was mapped to chromosome 11 in the soybean genome (Espinosa et al, 2015, Coleman et al, 2016. The gene is 8362 bp long and has 20 exons that code for 901 amino acids long protein (www.phytozome.net).…”