scholarly journals Studies on tissue transglutaminases: interaction of erythrocyte type-2 transglutaminase with GTP

1993 ◽  
Vol 291 (1) ◽  
pp. 37-39 ◽  
Author(s):  
C M Bergamini ◽  
M Signorini
Keyword(s):  
Binding Site ◽  
Reaction Rate ◽  
Nucleotide Binding ◽  
Time Dependent ◽  
Saturation Curve ◽  
Affinity Label ◽  
Gtp Binding ◽  
Label Probe ◽  
Modified Enzyme

Ca2+ and GTP are the main modulators of type-2 transglutaminases. To study the interaction of the enzyme with GTP, we have employed periodate-oxidized GTP as an affinity-label probe. Dialdehyde GTP bound irreversibly to type-2 transglutaminase in a time-dependent way with 1:1 stoichiometry at complete modification. The reaction took place in the absence, but was more rapid in the presence, of cyanoborohydride. Native GTP prevented incorporation of dialdehyde GTP, and Ca2+ significantly slowed down the reaction rate. The modified enzyme displayed decreased sensitivity to Ca2+, with a sigmoid saturation curve. We conclude that type-2 transglutaminase has a single GTP-binding site, the modification of which by dialdehyde GTP mimics nucleotide binding to the enzyme.

Characterization of Nucleotide Binding ­Site-Encoding Genes in Sweetpotato, Ipomoea batatas(L.) Lam., and Their Response to Biotic and Abiotic Stresses

2021 ◽  
pp. 1-15
Author(s):  
Zengzhi Si ◽  
Yake Qiao ◽  
Kai Zhang ◽  
Zhixin Ji ◽  
Jinling Han
Keyword(s):  
Binding Site ◽  
Abiotic Stresses ◽  
Ipomoea Batatas ◽  
Expression Profiles ◽  
Nucleotide Binding ◽  
Regulatory Elements ◽  
Nucleotide Binding Site ◽  
Biotic And Abiotic Stresses ◽  
Encoding Genes

Sweetpotato, <i>Ipomoea batatas</i> (L.) Lam., is an important and widely grown crop, yet its production is affected severely by biotic and abiotic stresses. The nucleotide binding site (NBS)-encoding genes have been shown to improve stress tolerance in several plant species. However, the characterization of NBS-encoding genes in sweetpotato is not well-documented to date. In this study, a comprehensive analysis of NBS-encoding genes has been conducted on this species by using bioinformatics and molecular biology methods. A total of 315 NBS-encoding genes were identified, and 260 of them contained all essential conserved domains while 55 genes were truncated. Based on domain architectures, the 260 NBS-encoding genes were grouped into 6 distinct categories. Phylogenetic analysis grouped these genes into 3 classes: TIR, CC (I), and CC (II). Chromosome location analysis revealed that the distribution of NBS-encoding genes in chromosomes was uneven, with a number ranging from 1 to 34. Multiple stress-related regulatory elements were detected in the promoters, and the NBS-encoding genes’ expression profiles under biotic and abiotic stresses were obtained. According to the bioinformatics analysis, 9 genes were selected for RT-qPCR analysis. The results revealed that <i>IbNBS75</i>, <i>IbNBS219</i>, and <i>IbNBS256</i> respond to stem nematode infection; <i>Ib­NBS240</i>, <i>IbNBS90</i>, and <i>IbNBS80</i> respond to cold stress, while <i>IbNBS208</i>, <i>IbNBS71</i>, and <i>IbNBS159</i> respond to 30% PEG treatment. We hope these results will provide new insights into the evolution of NBS-encoding genes in the sweetpotato genome and contribute to the molecular breeding of sweetpotato in the future.

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