Molecular analysis of the plant gene encoding cytosolic phosphoglucose isomerase.
The gene encoding a cytosolic isozyme of phosphoglucose isomerase (PGI, EC 5.3.1.9) was isolated from Clarkia lewisii, a wild flower native to California, and the structure and sequence of the entire coding region determined. PGI catalyzes an essential step in glycolysis and carbohydrate biosynthesis in plants. Spanning about 6 kb, the gene has 23 exons and 22 introns, the highest number yet reported in plants. The exons range in size from 43 to 156 nt and encode a protein of 569 amino acids. The protein is about 44-46% identical to the inferred protein sequences of pig, Escherichia coli and Saccharomyces cerevisiae. All of the introns are bordered with the consensus 5'-GT...AG-3' dinucleotides. The longest intron includes a large stem-loop structure bounded by a perfect 9 nt direct repeat. We cloned the PGI gene from a genomic library prepared from a single plant of known PGI genotype. The locus and allele of the clone were identified by matching restriction fragments to fragments from genetically defined genomic DNAs by Southern hybridization.
Thomas
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Department of Genetics, University of California, Davis 95616.
Laudencia-Chingcuanco
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Gottlieb
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D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003600:Cytosol / Q000201:enzymology*; D005091:Exons / Q000235:genetics; D015698:Genomic Library; D005956:Glucose-6-Phosphate Isomerase / Q000737:chemistry / Q000235:genetics*; D007438:Introns / Q000235:genetics; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010944:Plants / Q000201:enzymology* / Q000235:genetics; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping
D005956:Glucose-6-Phosphate Isomerase