Compilation of eukaryotic sequences around transcription initiation sites

All vertebrate and invertebrate sequences present in the GenBank database have been aligned according to their mRNA start sites. For some cases the regions between positions -110 and +110 are presented. Previously, two general transcription initiation signals have been noted, the universal TATA box at position -30 and the CAAT box at -75. Our analysis indicates the presence of other signals, at least as significant as the CAAT. Inspection of the aligned sequences reveals the high concentration of G + C near mRNA initiation sites in non-mammalian vertebrates and in mammalians.