• The Plant Pathology Journal
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• v.32 no.3
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• pp.266-272
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• 2016

A bacterial tyrosine sulfotransferase, RaxST, is required for activation of rice XA21-mediated immunity, and it catalyzes sulfation of tyrosine residues of Omp1X and RaxX in Xanthomonas oryzae pv. oryzae, a causal agent of bacterial blight in rice. Although RaxST is biochemically well-characterized, biological functions of tyrosine sulfation have not been fully elucidated. We compared protein expression patterns between the wildtype and a raxST knockout mutant using shotgun proteomic analysis. Forty nine proteins displayed a more than 1.5-fold difference in their expression between the wildtype and the mutant strains. Clusters of orthologous groups analysis revealed that proteins involved in cell motility were most abundant, and phenotypic observation also showed that the twitching motility of the mutant was dramatically changed. These results indicate that tyrosine sulfation by RaxST is essential for Xoo movement, and they provide new insights into the biological roles of RaxST in cellular processes.

• The Korean Journal of Zoology
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• v.33 no.4
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• pp.468-475
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• 1990

An In vitro protein sulfation in the soluble fraction of rat brain was charaderized further by an improved method of alkaline hydrolysis and thin layer ceflulose electrophoresis TLE) The protein sulfation was carried out in a reaction system containing [35 S] 3'-phosphoadenosine-5'-phosphosulfate (PAPS), Tris-maleate buffer (pH 8), MgCI$_2$, and soluble proteins from rat brain. The sulfated proteins were precipitated by acetone and alkaline hydrolysis was performed to obtain sulfated amino acids. The hydrolysate was separated further by TLE and the separated residues were identified by fluorography. The Iluorography of one-dimensional The showed at least nine sulfated residues including tryosine-O-sulfate. The other spots were not identified yet positively. General properties of protein sulfotransferases (PST) using this method were re-examined such as effects of concentrations of PAPS, pH, incubation temperature and $Mg^2$+. These results suggest a possible occurrence of several PST corresponding to each sulfated residue in rat brain and that the sulfation can occur not only in tyrosine but also in other residues as well.

• KSBB Journal
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• v.24 no.5
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• pp.458-462
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• 2009

Silk fibroin is a structural protein from Bombyx mori and can be sulfated to provide biofunctional polypeptides showing antiviral and anticoagulating activities. However, the sulfated fibroins have not been characterized enough to present their compositions and structures. In this report, sulfation reaction was investigated by varying the reaction temperature and sulfuric acid concentration and analysis of the resulting peptides were carried out. The degree of sulfation was proportion to sulfuric acid concentration but the maximum product yield was obtained at $60^{\circ}C$ and 5% of sulfuric acid concentration. FT-IR spectrum, UV absorption and NMR spectrum support that o-sulfate ester was formed at the hydroxyl group of serine and tyrosine residues. Size exclusion chromatography identified that sulfated fibroin was composed of a highly hydrolyzed polypeptide mixtures and peptides of relatively higher molecular weight.