Isolation and characterization of a histidine biosynthetic gene in Arabidopsis encoding a polypeptide with two separate domains for phosphoribosyl-ATP pyrophosphohydrolase and phosphoribosyl-AMP cyclohydrolase

Plant Physiol. 1998 Sep;118(1):275-83. doi: 10.1104/pp.118.1.275.

Abstract

Phosphoribosyl-ATP pyrophosphohydrolase (PRA-PH) and phosphoribosyl-AMP cyclohydrolase (PRA-CH) are encoded by HIS4 in yeast and by hisIE in bacteria and catalyze the second and the third step, respectively, in the histidine biosynthetic pathway. By complementing a hisI mutation of Escherichia coli with an Arabidopsis cDNA library, we isolated an Arabidopsis cDNA (At-IE) that possesses these two enzyme activities. The At-IE cDNA encodes a bifunctional protein of 281 amino acids with a calculated molecular mass of 31,666 D. Genomic DNA-blot analysis with the At-IE cDNA as a probe revealed a single-copy gene in Arabidopsis, and RNA-blot analysis showed that the At-IE gene was expressed ubiquitously throughout development. Sequence comparison suggested that the At-IE protein has an N-terminal extension of about 50 amino acids with the properties of a chloroplast transit peptide. We demonstrated through heterologous expression studies in E. coli that the functional domains for the PRA-CH (hisI) and PRA-PH (hisE) resided in the N-terminal and the C-terminal halves, respectively, of the At-IE protein.

MeSH terms

  • Amino Acid Sequence
  • Aminohydrolases / chemistry
  • Aminohydrolases / genetics*
  • Aminohydrolases / metabolism
  • Arabidopsis / enzymology
  • Arabidopsis / genetics*
  • Arabidopsis / metabolism*
  • Base Sequence
  • Catalytic Domain / genetics
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • DNA, Plant / genetics
  • Escherichia coli / genetics
  • Gene Expression
  • Genes, Plant*
  • Genetic Complementation Test
  • Histidine / biosynthesis*
  • Histidine / genetics*
  • Molecular Sequence Data
  • Mutation
  • Plant Proteins / chemistry
  • Plant Proteins / genetics*
  • Plant Proteins / metabolism
  • Pyrophosphatases / chemistry
  • Pyrophosphatases / genetics*
  • Pyrophosphatases / metabolism
  • Sequence Homology, Amino Acid

Substances

  • DNA, Complementary
  • DNA, Plant
  • Plant Proteins
  • Histidine
  • Aminohydrolases
  • phosphoribosyl-AMP cyclohydrolase
  • Pyrophosphatases
  • phosphoribosyl-ATP pyrophosphatase

Associated data

  • GENBANK/AB006082
  • GENBANK/AB006083