| D | d4n9id2 | All alpha proteins | DNA/RNA-binding 3-helical bundle | 'Winged helix' DNA-binding domain | CAP C-terminal domain-like | Catabolite gene activator protein (CAP), C-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| D | d4n9id1 | All beta proteins | Double-stranded beta-helix | cAMP-binding domain-like | cAMP-binding domain | Catabolite gene activator protein, N-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| C | d4n9ic2 | All alpha proteins | DNA/RNA-binding 3-helical bundle | 'Winged helix' DNA-binding domain | CAP C-terminal domain-like | Catabolite gene activator protein (CAP), C-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| C | d4n9ic1 | All beta proteins | Double-stranded beta-helix | cAMP-binding domain-like | cAMP-binding domain | Catabolite gene activator protein, N-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| B | d4n9ib2 | All alpha proteins | DNA/RNA-binding 3-helical bundle | 'Winged helix' DNA-binding domain | CAP C-terminal domain-like | Catabolite gene activator protein (CAP), C-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| B | d4n9ib1 | All beta proteins | Double-stranded beta-helix | cAMP-binding domain-like | cAMP-binding domain | Catabolite gene activator protein, N-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| A | d4n9ia2 | All alpha proteins | DNA/RNA-binding 3-helical bundle | 'Winged helix' DNA-binding domain | CAP C-terminal domain-like | Catabolite gene activator protein (CAP), C-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |
| A | d4n9ia1 | All beta proteins | Double-stranded beta-helix | cAMP-binding domain-like | cAMP-binding domain | Catabolite gene activator protein, N-terminal domain | (Escherichia coli ) [TaxId: 562 ], | SCOPe (2.08) |