Sequence comparison of TM-V and TM-VI helices within various GPCRs
| TM-V | TM-VI | |
|---|---|---|
| 227 238 | 347 351 | |
| ‖ ‖ | ‖ ‖ | |
| CCKB(rat) | SVLLLLLLFFIPGVVIAVAYGLIS | MLLVIVLLFFLCWLPVYSVNT |
| CCKA(human) | HTFLLLILFLIPGIVMMVAYGLIS | MLIVIVVLFFLCWMPIFSANA |
| NK-1 (human) | HICVTVLIYFLPLLVIGYAYTVVG | MMIVVVCTFAICWLPFHIFFL |
| BK (human) | NMLLNVVGFLLPLSVITFCTMQIM | LVLVVLLLFIICWLPFQISTF |
| AT1 (human) | GLTKNILGFLFPFLIILTSYTLIW | IIMAIVLFFFFSWIPHQIFTF |
| 5-HT2(human) | VLIGSFVSFFIPLTIMVITYFLTI | VLGIVFFLFVVMWCPFFITNI |
| M1 (human) | TFGTAMAAFYLPVTVMCTLYWRIY | TLSAILLAFILTWTPYNIMVL |
| β2-AR (human) | AIASSIVSFYVPLVIMVFVYSRVF | TLGIIMGTFTLCWLPFFIVNI |
The predicted TM helices of the rat CCKB receptor are compared with the corresponding sequences of other representative members of the GPCRs. Numbers above the sequences refer to amino acid positions within the rat CCKB receptor (NK-1, neurokinin-1 receptor; BK, bradykinin receptor; AT-1, angiotensin receptor type 1; 5HT2, 5-hydroxytryptamine receptor type 2; M1, muscarinic receptor type 1; β2-AR, β2 adrenergic receptor). The single-letter amino acid code is used. The highly conserved aromatic residues are indicated in bold.