Molecular cloning and sequence analysis of the human cytosolic aspartate aminotransferase gene

Structural organization of the human cytosolic aspartate aminotransferase gene was determined by analyzing the phage clones obtained from two kinds of genomic DNA libraries, using mouse cytosolic aspartate aminotransferase cDNA as a probe. The gene is more than 32 kb long and is split into 9 exons by 8 introns of various sizes. The 5' and 3'-flanking regions and the exact sizes and boundaries of the exon blocks were determined. The 5' end of the gene lacks the TATA and CAAT boxes, but contains G+C rich sequences and one potential binding site for the transcription factor, Sp1. Comparison of the nucleotide sequence of 250 bp upstream from the translation-initiation site revealed that the sequences of binding sites for the nuclear proteins, previously identified in the mouse, are highly conserved between human and mouse cytosolic aspartate aminotransferase genes.