Figure 3.

Length distribution of 5' UTRs in TATA-containing and TATA-less genes. The length of the 5' UTR of all 12,749 genes (orange bars) shows an average of 129 nt. Promoters lacking a TATA box (TATA-less, red bars) have in average 5' UTRs 138 nt long. The 5' UTR of TATA-containing genes (blue bars) are in average 108 nt long.