Glucose-1-phosphate uridylyltransferase from Erwinia amylovora: Activity, structure and substrate specificity.Benini, S., Toccafondi, M., Rejzek, M., Musiani, F., Wagstaff, B.A., Wuerges, J., Cianci, M., Field, R.A.
(2017) Biochim Biophys Acta 1865: 1348-1357
- PubMed: 28844747
- DOI: 10.1016/j.bbapap.2017.08.015
- Primary Citation of Related Structures:
- PubMed Abstract:
- Expression, purification, crystallization and preliminary X-ray analysis of glucose-1-phosphate uridylyltransferase (GalU) from Erwinia amylovora.
Toccafondi, M., Cianci, M., Benini, S.
(2014) Acta Crystallogr F Struct Biol Commun 70: 1249
Erwinia amylovora, a Gram-negative plant pathogen, is the causal agent of Fire Blight, a contagious necrotic disease affecting plants belonging to the Rosaceae family, including apple and pear. E. amylovora is highly virulent and capable of rapid dissemination in orchards; effective control methods are still lacking ...
Erwinia amylovora, a Gram-negative plant pathogen, is the causal agent of Fire Blight, a contagious necrotic disease affecting plants belonging to the Rosaceae family, including apple and pear. E. amylovora is highly virulent and capable of rapid dissemination in orchards; effective control methods are still lacking. One of its most important pathogenicity factors is the exopolysaccharide amylovoran. Amylovoran is a branched polymer made by the repetition of units mainly composed of galactose, with some residues of glucose, glucuronic acid and pyruvate. E. amylovora glucose-1-phosphate uridylyltransferase (UDP-glucose pyrophosphorylase, EC 188.8.131.52) has a key role in amylovoran biosynthesis. This enzyme catalyses the production of UDP-glucose from glucose-1-phosphate and UTP, which the epimerase GalE converts into UDP-galactose, the main building block of amylovoran. We determined EaGalU kinetic parameters and substrate specificity with a range of sugar 1-phosphates. At time point 120min the enzyme catalysed conversion of the sugar 1-phosphate into the corresponding UDP-sugar reached 74% for N-acetyl-α-d-glucosamine 1-phosphate, 28% for α-d-galactose 1-phosphate, 0% for α-d-galactosamine 1-phosphate, 100% for α-d-xylose 1-phosphate, 100% for α-d-glucosamine 1-phosphate, 70% for α-d-mannose 1-phosphate, and 0% for α-d-galacturonic acid 1-phosphate. To explain our results we obtained the crystal structure of EaGalU and augmented our study by docking the different sugar 1-phosphates into EaGalU active site, providing both reliable models for substrate binding and enzyme specificity, and a rationale that explains the different activity of EaGalU on the sugar 1-phosphates used. These data demonstrate EaGalU potential as a biocatalyst for biotechnological purposes, as an alternative to the enzyme from Escherichia coli, besides playing an important role in E. amylovora pathogenicity.
Department of Biological Chemistry, John Innes Centre, Norwich Research Park, Norwich NR4 7UH, UK.