• Journal of the Korean Magnetic Resonance Society
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• v.21 no.2
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• pp.50-54
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• 2017

Cupin-superfamily proteins represent the most functionally diverse groups of proteins and include a huge number of functionally uncharacterized proteins. Recently, YaiE, a cupin protein from Escherichia coli has been suggested to be involved in a novel activity of pyrimidine/purine nucleoside phosphorylase (PPNP). In the present study, we achieved a complete backbone NMR assignments of YaiE, by a series of heteronuclear multidimensional NMR experiments on its [$^{13}C/^{15}N$]-enriched sample. Subsequently, secondary structure analysis using the assigned chemical shift values identified 10 obvious ${\beta}-strands$ and a tentative $3_{10}-helix$. Taken all together, the results constitute the first structural characterization of a putative PPNP cupin protein.

• The Plant Pathology Journal
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• v.37 no.6
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• pp.555-565
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• 2021

Bacteriophages infecting Acidovorax citrulli, the causal agent of bacterial fruit blotch, have been proven to be effective for the prevention and control of this disease. However, the occurrence of bacteriophage-resistant bacteria is one of hurdles in phage biocontrol and the understanding of phage resistance in this bacterium is an essential step. In this study, we aim to investigate possible phage resistance of A. citrulli and relationship between phage resistance and pathogenicity, and to isolate and characterize the genes involved in these phenomena. A phage-resistant and less-virulent mutant named as AC-17-G1 was isolated among 3,264 A. citrulli Tn5 mutants through serial spot assays and plaque assays followed by pathogenicity test using seed coating method. The mutant has the integrated Tn5 in the middle of a cupin protein gene. This mutant recovered its pathogenicity and phage sensitivity by complementation with corresponding wild-type gene. Site-directed mutation of this gene from wild-type by CRISPR/Cas9 system resulted in the loss of pathogenicity and acquisition of phage resistance. The growth of AC-17-G1 in King's B medium was much less than the wild-type, but the growth turned into normal in the medium supplemented with D-mannose 6-phosphate or D-fructose 6-phosphate indicating the cupin protein functions as a phosphomannos isomerase. Sodium dodecyl sulfa analysis of lipopolysaccharide (LPS) extracted from the mutant was smaller than that from wild-type. All these data suggest that the cupin protein is a phosphomannos isomerase involved in LPS synthesis, and LPS is an important determinant of pathogenicity and phage susceptibility of A. citrulli.

• BMB Reports
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• v.42 no.6
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• pp.387-392
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• 2009

Here, we report the first biochemical and structural characterization of the hypothetical protein HP0902 from Helicobacter pylori, in terms of structural genomics. Gel-permeation chromatography and dynamic light scattering indicated that the protein behaves as a dimer in solution. Circular dichroism spectroscopy showed that HP0902 primarily adopts a $\beta$-structure and the protein was highly thermostable with a denaturing temperature higher than $70^{\circ}C$. Finally, the backbone NMR assignments were obtained on the [$^{13}C,^{15}N$]HP0902 and the secondary structure was determined using the chemical shift data. Additionally, the local flexibility was assessed via a heteronuclear $^1H-^{15}N$ steady state NOE experiment. The results revealed that HP0902 would adopt a compactly folded, all-$\beta$ topology with 11 $\beta$-strands. All of the results clearly support the notion that HP0902 belongs to the cupin superfamily of proteins.

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.48-54
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• 2013

BACKGROUND: Sorghum (Sorghum bicolor (L.) Moench) ranks as the 6th most planted crop in the world behind wheat, rice, maize, soybean, and barley. The objective of this study was to identify bio-marker among sorghum cultivars using proteomics approach such as two-dimensional polyacrylamide gel electrophoresis (2-DE) coupled with mass spectrometry (MS). METHODS AND RESULTS: Proteins were extracted from sorghum seed, and separated by 2-DE. Total 652 spots were detected from 4 different sorghum seed after staining of 2-DE with colloidal Coomassie brilliant blue (CBB). Among them, 8 spots were differentially expressed and were identified using MALDI-TOF/TOF mass spectrometry. They were involved in RNA metabolism (spot1, spot 4), heat shock proteins (HSPs, spot 2), storage proteins (spot 3, spot 5, and spot 6), and redox related proteins (spot 8). Eight of these proteins were highly up-regulated in Whinchalsusu (WCS). The HSPs, Cupin family protein, and Globulin were specifically accumulated in WCS. The DEAD-box helicase was expressed in 3 cultivars except for WCS. Ribonuclease T2 and aldo-keto reductase were only expressed in 3 cultivars except for Daepung-susu (DPS). CONCLUSION(S): Functions of identified proteins were mainly involved in RNA metabolism, heat shock protein (HSP), and redox related protein. Thus, they may provide new insight into a better understanding of the charactreization between the cultivars of sorghum.