Cloning, characterization and mRNA expression analysis of PVAS1, a type I asparagine synthetase gene from Phaseolus vulgaris.
A gene encoding a putative asparagine synthetase (AS; EC 6.3.5.4) has been isolated from common bean (Phaseolus vulgaris L.). A 2-kb cDNA clone of this gene (PVAS1) encodes a protein of 579 amino acids with a predicted molecular mass of 65,265 Da, an isoelectric point of 6.3, and a net charge of -9.3 at pH 7.0. The PVAS1 protein sequence conserves all the amino acid residues that are essential for glutamine-dependent AS, and PVAS1 complemented an Escherichia coli asparagine auxotroph, which demonstrates that it encodes a glutamine-dependent AS. The PVAS1 protein showed the highest similarity to soybean SAS1, and piled up with other legume ASs to form an independent dendritic group of type-I AS enzymes. Northern blot analyses revealed that the expression pattern of PVAS1 resembles that of PVAS2, another AS previously described in the common bean. Unlike PVAS2, however, PVAS1 was not expressed in the nodule and was not repressed by light, suggesting different functions for these two AS genes.
Osuna
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Departamento de Bioquímica y Biología Molecular, Instituto Andaluz de Biotecnología, Universidad de Córdoba, Spain.
Gálvez-Valdivieso
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G
Piedras
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Pineda
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Aguilar
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D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001217:Aspartate-Ammonia Ligase / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D018744:DNA, Plant; D018506:Gene Expression Regulation, Plant; D006863:Hydrogen-Ion Concentration; D007526:Isoelectric Point; D008969:Molecular Sequence Data; D008970:Molecular Weight; D027805:Phaseolus / Q000201:enzymology / Q000235:genetics*; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016415:Sequence Alignment; D013025:Glycine max / Q000235:genetics / Q000378:metabolism
D018744:DNA, Plant; D010940:Plant Proteins; D012333:RNA, Messenger; D001217:Aspartate-Ammonia Ligase