Identification and characterization of a gene encoding for a nucleotidase from Phaseolus vulgaris

• Published in: Journal of plant physiology Vol. 185; pp. 44 - 51
• Main Authors: Cabello-Díaz, Juan Miguel, Gálvez-Valdivieso, Gregorio, Caballo, Cristina, Lambert, Rocío, Quiles, Francisco Antonio, Pineda, Manuel, Piedras, Pedro
• Format: Journal Article
• Language: English
• Published: Germany Elsevier GmbH 01-08-2015
• Subjects: Amino Acid Sequence; Escherichia coli - genetics; Gene Expression; Germination; Nucleoside; Nucleotidase; Nucleotidases - chemistry; Nucleotidases - genetics; Nucleotidases - metabolism; Nucleotide monophosphate; Phaseolus - genetics; Phaseolus - metabolism; Phaseolus vulgaris; Phosphatase; Plant Proteins - chemistry; Plant Proteins - genetics; Plant Proteins - metabolism; Recombinant Proteins - genetics; Recombinant Proteins - metabolism; Sequence Alignment; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Tandem Mass Spectrometry; Ureide synthesis; Nucleotidase; Ureide synthesis; Phaseolus vulgaris; Germination; Nucleotide monophosphate; Nucleoside; Phosphatase
• ISSN: 0176-1617; 1618-1328
• DOI: 10.1016/j.jplph.2015.07.008

Nucleotidases are phosphatases that catalyze the removal of phosphate from nucleotides, compounds with an important role in plant metabolism. A phosphatase enzyme, with high affinity for nucleotides monophosphate previously identified and purified in embryonic axes from French bean, has been analyzed by MALDI TOF/TOF and two internal peptides have been obtained. The information of these peptide sequences has been used to search in the genome database and only a candidate gene that encodes for the phosphatase was identified (PvNTD1). The putative protein contains the conserved domains (motif I–IV) for haloacid dehalogenase-like hydrolases superfamily. The residues involved in the catalytic activity are also conserved. A recombinant protein overexpressed in Escherichia coli has shown molybdate resistant phosphatase activity with nucleosides monophosphate as substrate, confirming that the identified gene encodes for the phosphatase with high affinity for nucleotides purified in French bean embryonic axes. The activity of the purified protein was inhibited by adenosine. The expression of PvNTD1 gene was induced at the specific moment of radicle protrusion in embryonic axes. The gene was also highly expressed in young leaves whereas the level of expression in mature tissues was minimal.