Isolation, characterization, and chromosomal location of a gene encoding the delta 1-pyrroline-5-carboxylate synthetase in Arabidopsis thaliana.
A full-length cDNA and the corresponding At-P5S gene encoding the first enzyme of the proline biosynthetic pathway, the delta 1-pyrroline-5-carboxylate (P5C) synthetase, were isolated in Arabidopsis thaliana. The At-P5S cDNA encodes a protein of 717 amino acids showing high identity with the P5C synthetase of Vigna aconitifolia. Strong homology is also found at the N-terminus to bacterial and yeast gamma-glutamyl kinase and at the C-terminus to bacterial gamma-glutamyl phosphate reductase. Putative ATP- and NAD(P)H-binding sites are suggested in the At-P5S protein. The transcribed region of the At-P5S gene is 4.8 kb long and contains 20 exons. Southern analysis suggests the presence of only one At-P5S gene in the A. thaliana genome mapped at the bottom of the chromosome two. Expression analysis of At-P5S in different organs reveals abundant At-P5S transcripts in mature flowering plant. Rapid induction of the At-P5S gene followed by accumulation of proline was observed in NaCl-treated seedlings suggesting that At-P5S is osmoregulated.
Savouré
A
A
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Jaoua
S
S
Hua
X J
XJ
Ardiles
W
W
Van Montagu
M
M
Verbruggen
N
N
D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; D000445:Aldehyde Oxidoreductases / Q000737:chemistry; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017931:DNA Primers / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D018506:Gene Expression Regulation, Plant / Q000235:genetics; D017343:Genes, Plant; D050698:Glutamate-5-Semialdehyde Dehydrogenase; D016350:Leucine Zippers / Q000235:genetics; D008969:Molecular Sequence Data; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017851:Phosphotransferases (Carboxyl Group Acceptor) / Q000737:chemistry; D016133:Polymerase Chain Reaction; D011392:Proline / Q000096:biosynthesis; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology; D014158:Transcription, Genetic / Q000235:genetics
D017931:DNA Primers; D018076:DNA, Complementary; D012965:Sodium Chloride; D011392:Proline; D000445:Aldehyde Oxidoreductases; D050698:Glutamate-5-Semialdehyde Dehydrogenase; D050842:1-Pyrroline-5-Carboxylate Dehydrogenase; D000587:Oxidoreductases Acting on CH-NH Group Donors; D017851:Phosphotransferases (Carboxyl Group Acceptor); C020650:glutamate 5-kinase