A nuclear gene encoding β-amylase of sweet potato

Yoshida, Nobumasa; Hayashi, Kôji; Nakamura, Kenzo

doi:10.1016/0378-1119(92)90101-t

Cited by 20 publications

(1 citation statement)

References 12 publications

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“…The enzyme is encoded by a single copy of the Amyβ gene per haploid genome [ [21] , [22] , [23] ], located on chromosome 13. The genomic DNA for Amyβ is about 4.8 kb and the cDNA is 2.8 kb.…”

Section: Introductionmentioning

confidence: 99%

Analysis of β-amylase gene (Amyβ) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa

Banda

Kyallo

Entfellner

et al. 2021

Journal of Agriculture and Food Research

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β-amylase is a thermostable enzyme that hydrolyses starch during cooking of sweetpotato ( Ipomoea batatas ) storage roots, thereby influencing eating quality. Its activity is known to vary amongst genotypes but the genetic diversity of the beta-amylase gene ( Amyβ ) is not well studied. Amyβ has a highly conserved region between exon V and VI, forming part of the enzyme's active site. To determine the gene diversity, a 2.3 kb fragment, including the conserved region of the Amyβ gene was sequenced from 25 sweetpotato genotypes. The effect of sequence variation on gene expression, enzyme activity, and firmness in cooked roots was determined. Six genotypes carrying several SNPs within exon V, linked with an AT or ATGATA insertion in intron V were unique and clustered together. The genotypes also shared an A336E substitution in the amino acid sequence, eight residues upstream of a substrate-binding Thr344. The genotypes carrying this allele exhibited low gene expression and low enzyme activity. Enzyme activity was negatively correlated with firmness (R = −0.42) in cooked roots. This is the first report of such an allele, associated with low enzyme activity. These results suggest that genetic variation within the AmyB locus can be utilized to develop markers for firmness in sweetpotato breeding.

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Section: Introductionmentioning

confidence: 99%

Analysis of β-amylase gene (Amyβ) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa

Banda

Kyallo

Entfellner

et al. 2021

Journal of Agriculture and Food Research

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Evolution of β-amylase: Patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms

et al. 1996

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Evolution of β-amylase: Patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms

Pujadas¹,

Ramírez²,

Valero³

et al. 1996

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Soybean and sweet potato beta-amylases are structured as alpha/beta barrels and the same kind of folding may account for all known beta-amylases. We provide a comprehensive analysis of both protein and DNA (coding region) sequences of beta-amylases. The aim of the study is to contribute to the knowledge of the evolutionary molecular relationships among all known beta-amylases. Our approach combines the identification of the putative eightfold structural core formed by beta-strands with a complete multi-alignment analysis of all known sequences. Comparing putative beta-amylase (alpha/beta)8 cores from plants and microorganisms, two differentiated versions of residues at the packing sites, and a unique set of eight identical residues at the C-terminal catalytical site are observed, indicating early evolutionary divergence and absence of localized three-dimensional evolution, respectively. A new analytical approach has been developed in order to work out conserved motifs for beta-amylases, mostly related with the enzyme activity. This approach appears useful as a new routine to find sets of motifs (each set being known as a fingerprint) in protein families. We demonstrate that the evolutionary mechanism for beta-amylases is a combination of parsimonious divergence at three distinguishable rates in relation to the functional signatures, the barrel scaffold, and alpha-helix-containing loops.

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A nuclear gene encoding β-amylase of sweet potato

Cited by 20 publications

References 12 publications

Analysis of β-amylase gene (Amyβ) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa

Analysis of β-amylase gene (Amyβ) variation reveals allele association with low enzyme activity and increased firmness in cooked sweetpotato (Ipomoea batatas) from East Africa

Evolution of β-amylase: Patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms

Evolution of β-amylase: Patterns of variation and conservation in subfamily sequences in relation to parsimony mechanisms

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