Structure of the gene encoding pig phosphoglucose isomerase

Genomic clones encoding pig phosphoglucose isomerase (PGI) have been isolated and partially sequenced. The gene (Pgi) contains 18 exons, 17 introns and spans about 32 kb. This structure is partially conserved between plant and animal. A major transcription start point (tsp) has been identified 74 nucleotides (nt) upstream from the AUG. The nt sequence around the tsp is very G+C rich; a 5'-ATAAA sequence, as well as four putative Sp1-binding sites, are present. In the 3'-flanking region, an AATAAA signal has been identified. Extending from the 5'-flanking region to the first intron, a 0.6-kb CpG island has been identified. The Pgi structural gene contains several DNA repetitive elements in its non-coding regions.