STRUCTURE OF THE GENE ENCODING POTATO CYTOSOLIC PYRUVATE-KINASE

The polymerase chain reaction (PCR) has been used to generate a series of overlapping genomic clones representing 43 bp of 5' untranslated sequence, 63 bp of 3' untranslated sequence and the entire coding sequence of the gene encoding potato cytosolic pyruvate kinase (PK(c)). This portion of the gene is approximately 4.5 kb in length and is interrupted by three introns, one of which is present in the 5' untranslated region. Southern blot analysis indicates that PK(c) is encoded by a small gene family, and sequence data from a number of PCR-derived genomic clones indicate that there are as many as six PK(c) genes. Sequence differences between the PCR-generated genomic clones and a PK(c) cDNA clone are discussed with respect to the fidelity of Taq polymerase. An alignment of intron placement in the potato PK(c) gene with intron placement in PK genes from other sources indicates that two of the potato introns correspond to intron positions in other species.