Table 1. DNA recognition sequence of PAS heterodimers.
| Heterodimer | Name1 | Sequence2 |
| Sim/Tgo | CME | ACGTG |
| Trh/Tgo | CME | ACGTG |
| Dys/Tgo | TCGTG | |
| Dys/Tgo | GCGTG 3 | |
| Dys/Tgo | CME | ACGTG 3 |
| Sima/Tgo | HRE | RCGTG |
| Ss/Tgo | XRE | TNGCGTG |
| Per/Tim | E box | CACGTG |
| Clock/Bmal | E box | CACGTG |
1 The names of the recognition sites are indicated: CNS midline enhancer (CME), hypoxia response element (HRE), xenobiotic response element (XRE) and the E box is the recognition site for bHLH proteins. Similar (Sima) is the fly hypoxia inducible factor-α, Spineless (Ss) functions in bristle, leg and antennal development and Period (Per), Timeless (Tim), Clock and Bmal function in circadian rhythms.
2 The CGTG core sequences shared by each recognition site are italicized.
3 The GCGTG and ACGTG sites are likely low affinity sites for Dys/Tgo [58].