G G G P S V V
L L R A E I I
U P F C C P S
group 1
(orange)
L2 SSS AA AAAV SSSS SS SSS SSS Ligand
121 LLL FF AIII LLLL LL LLL LLL Helix 1 (middle)
709 FFF TT LLLL FFFF FF FFF FFF Helix 7 (top)
group 2
(red)
L3 QQQ EE DDDD DDDD DD DDD DDD Ligand
N71 FFF FF WWWW WWWW WW WWW WWW N terminus
N114 QQQ IL WWWW WWWW WW WWW WWW N terminus
N130 QQQ EE AAAA AAAA AA AAA AAA N terminus
316 RRR RR KKKK KKKK KK KKK KKK Helix 3 (top)
E462 TTT TT DDDD DDDD DD DDD DDD E-loop 4-5
510 AAA AA SSSS SSSS SS SSS SSS Helix 5 (top)
612 LLL LL FFFF FFFF FF FFF FFF Helix 6 (middle)
616 EEE EE YYYY YYYY YY YYY YYY Helix 6 (middle)
623 TTT MM PPPP PPPP PP PPP PPP Helix 6 (top)
714 SSS TT GGGG GGGG GG GGG GGG Helix 7 (top)
group 3
(lila)
L4 GGG GG AAAA GGGG GG AAA AAA Ligand
330 YYY YY FFFF YYYY YY FFF FFF Helix 3 (middle)
group 4
(yellow)
L5 TTT TT IIII IIII TT VVV VVV Ligand
N68 NNN NN PPPP PPPP EE SSS SSS N terminus
group 5
(light grey)
L10 YYY VV YYYY YYYY LL YYY YYY Ligand
Cter RRR KK RRRR RRRR KK RRR RRR C terminus
group 6
(brown)
L11 SSS SS RRRR SSSS SS TTT TTT Ligand
427 VVV VV TTTT VVVV VV TII III Helix 4 (top)
group 7
(black)
L12 KKK SS KRKK RRRR RR RRR RRR Ligand
720 LLL MM IVII VVVV VV VVV VVV Helix 7 (middle)
group 8
(dark grey)
L15 DDD EE GGGS KKKK DE KKK KKK Ligand
L17 RRR QQ LLLL MMMM AA MMM MMM Ligand
N75 SSS AA LLLL TTTT SS TTT TTT N terminus
Cter PPP SS RRAR GGGG NH GGG GGG C terminus
group 9
(light green)
L16 SSS GG QQQQ QQQQ SG QQQ QQQ Ligand
L21 DDD EE KKKK KKKK RR KKK KKK Ligand
N97 YCH AA FFFF FFFF LL FFF FFF N terminus
109 YQF LL VVVV VVVV LL VVV VVV Helix 1 (top)
group 10
(dark green)
L22 FFF FF LLLV YYYY LL YYY YYY Ligand
527 AAA AS RRRR QQQQ RR QQQ QQQ Helix 5 (bottom)
group 11
(light blue)
L25 WWW WW DEDD AAAA GG SSS SSS Ligand
E463 SSS RR LLLL MMMM II TTT TTT E-loop 4-5
group 12
(dark blue)
L26 LLL LL IIII VVVV LL III III Ligand
E497 MMM MM SSSS TTTT AA SSS SSS E-loop 4-5
group 13
(purple)
L27 MMM VV MMMM LLLL VV LLL LLL Ligand
I533 QQQ LL QQQQ DDDD EE DDD DDD I-loop 5-6
Table 1. Groups of highly correlated sequence positions. The numbers in brackets starting with L indicate the position in the ligand; Nx indicates location in the receptor N-terminus; Cx indicates location in the receptor C-terminus; Ex indicates position in external loop and Ix in intracellular loop; plain numbers are the so-called helix position numbers (the first digit indicates the helix, the last two digits are selected such that the most conserved residue in each helix has a nice round number). The amino acid types in the 21 sequences at these positions are listed horizontally next to each other. The putative position in the receptor is indicated in the right hand column.
References 11 and 12 explain the residue numbering in detail. The group numbers and their corresponding colour in the snake diagram are indicated.
F. Horn et al. 26-Sep-1997