HCA1 receptor - Gi1

GPCR CLASS (FAMILY)

Class A (Rhodopsin)

GPCR SPECIES

Homo sapiens

GPCR PREFERRED CHAIN

R

G PROTEIN (FAMILY)

Gi/o

G PROTEIN SPECIES

Homo sapiens

PDB CODE

9KT9

RESOLUTION

2.7 Å

REFERENCE

10.1021/ACS.JMEDCHEM.4C02567

PUBLICATION DATE

Dec. 10, 2025

3D VIEW

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LIGAND INTERACTIONS

24 interactions (Click to see)

LIGANDS

3,5-dihydroxybenzoic acid - Agonist pubchem gtoplig chembl_ligand

PHYSIOLOGICAL LIGANDS

D-lactic acid



GPCR - G protein interface interactions



The biflare plot is a modified version of a flareplot, where lines are drawn between an inner concentric circle (Gα residues) and an outer concentric circle (GPCR residues) depicting the interface interactions.
Different interaction types are shown with different line types (aromatic - solid, hydrophobic - dashed, ionic - long dashed, polar - dotted, Van der Waals - dash-dot).
The interactive features include filtering on interaction type, segments, residues and backbone or sidechain interactions.


Interaction definitions:

Residue numbering:

GPCR-G protein backbone (bb) or sidechain (sc):





Structures

Sequence Color

Gα, Gβ, Gγ, GPCR
Interaction cut-off: strict (stick), loose (line)

NGL is a WebGL based 3D viewer powered by MMTF.

Interaction
type		 GPCR
Segment
AA
Number		 Generic
number		 Gα
segment
AA
Number		 Generic
number
Ionic TM3 K 116 3x53 G.H5 D 350 G.H5.22
Polar TM3 K 116 3x53 G.H5 D 350 G.H5.22
Polar C-term S 282 - G.H5 G 352 G.H5.24
Van-der-waals C-term S 282 - G.H5 G 352 G.H5.24
Hydrophobic TM5 L 203 5x65 G.H5 I 344 G.H5.16
Hydrophobic C-term P 283 - G.H5 F 354 G.H5.26
Hydrophobic ICL2 P 120 - G.H5 I 344 G.H5.16
Hydrophobic ICL3 Q 208 - G.h4s6 E 318 G.h4s6.12
Van-der-waals ICL3 Q 208 - G.h4s6 E 318 G.h4s6.12
Polar C-term S 284 - G.H5 K 349 G.H5.21
Polar TM6 R 214 6x29 G.h4s6 D 315 G.h4s6.09
Hydrophobic TM6 M 215 6x30 G.H5 L 348 G.H5.20
Van-der-waals TM6 M 215 6x30 G.H5 L 348 G.H5.20
Hydrophobic TM6 A 218 6x33 G.H5 L 353 G.H5.25
Van-der-waals TM6 A 218 6x33 G.H5 L 353 G.H5.25
Hydrophobic ICL2 P 120 - G.H5 T 340 G.H5.12
Hydrophobic ICL3 L 209 - G.H5 K 345 G.H5.17
Van-der-waals ICL3 L 209 - G.H5 K 345 G.H5.17
Hydrophobic TM6 I 222 6x37 G.H5 L 353 G.H5.25
Van-der-waals TM6 I 222 6x37 G.H5 L 353 G.H5.25
Polar ICL2 T 126 - G.hns1 R 32 G.hns1.03
Hydrophobic ICL2 T 126 - G.hns1 R 32 G.hns1.03
Van-der-waals ICL2 T 126 - G.hns1 R 32 G.hns1.03
Hydrophobic TM5 L 203 5x65 G.H5 L 348 G.H5.20
Hydrophobic ICL3 L 209 - G.H5 D 341 G.H5.13
Hydrophobic ICL3 Q 208 - G.S6 Y 320 G.S6.02
Van-der-waals ICL3 Q 208 - G.S6 Y 320 G.S6.02
Hydrophobic ICL3 R 206 - G.H5 I 344 G.H5.16
Van-der-waals ICL3 R 206 - G.H5 I 344 G.H5.16
Hydrophobic TM6 M 215 6x30 G.H5 F 354 G.H5.26
Van-der-waals TM6 M 215 6x30 G.H5 F 354 G.H5.26
Hydrophobic TM6 F 221 6x36 G.H5 L 353 G.H5.25
Van-der-waals TM6 F 221 6x36 G.H5 L 353 G.H5.25
Hydrophobic TM2 S 50 2x39 G.H5 C 351 G.H5.23
Hydrophobic TM2 K 48 2x37 G.H5 D 350 G.H5.22
Van-der-waals TM2 K 48 2x37 G.H5 D 350 G.H5.22
Hydrophobic TM3 V 117 3x54 G.H5 L 348 G.H5.20
Polar TM3 K 116 3x53 G.H5 N 347 G.H5.19
Hydrophobic TM3 K 116 3x53 G.H5 N 347 G.H5.19
Van-der-waals TM3 K 116 3x53 G.H5 N 347 G.H5.19
Polar TM6 Q 212 6x27 G.h4s6 D 315 G.h4s6.09
Van-der-waals TM6 Q 212 6x27 G.h4s6 D 315 G.h4s6.09
Ionic ICL3 R 206 - G.H5 D 341 G.H5.13
Polar ICL3 R 206 - G.H5 D 341 G.H5.13
Hydrophobic ICL3 R 206 - G.H5 D 341 G.H5.13
Hydrophobic TM3 R 113 3x50 G.H5 C 351 G.H5.23
Hydrophobic ICL2 H 121 - G.H5 I 343 G.H5.15
Van-der-waals ICL2 H 121 - G.H5 I 343 G.H5.15
Polar ICL2 H 121 - G.H5 T 340 G.H5.12
Hydrophobic ICL2 H 121 - G.H5 T 340 G.H5.12
Van-der-waals ICL2 H 121 - G.H5 T 340 G.H5.12
Hydrophobic TM3 K 116 3x53 G.H5 C 351 G.H5.23
Van-der-waals TM3 K 116 3x53 G.H5 C 351 G.H5.23
Hydrophobic TM6 R 214 6x29 G.H5 F 354 G.H5.26
Van-der-waals TM6 R 214 6x29 G.H5 F 354 G.H5.26
Hydrophobic C-term F 285 - G.H5 G 352 G.H5.24
Aromatic ICL2 H 121 - G.H5 F 336 G.H5.08
Hydrophobic ICL2 H 121 - G.H5 F 336 G.H5.08
Polar TM6 R 214 6x29 G.h4s6 T 316 G.h4s6.10
Polar TM3 D 112 3x49 G.H5 C 351 G.H5.23
Hydrophobic ICL2 P 120 - G.H5 I 343 G.H5.15
Polar ICL3 Q 208 - G.S6 I 319 G.S6.01
Van-der-waals ICL3 Q 208 - G.S6 I 319 G.S6.01
Polar TM2 S 50 2x39 G.H5 D 350 G.H5.22
Van-der-waals TM2 S 50 2x39 G.H5 D 350 G.H5.22
Hydrophobic ICL2 H 121 - G.S3 L 194 G.S3.01