9PDO: Arginine-bound CASTOR1 from Homo sapiens

Arginine-bound CASTOR1 from Homo sapiens (GATOR2-inspired update). Determined by X-ray diffraction at 1.8 Å resolution. Released 12 Aug 2026.

Method: X-ray diffraction
Resolution: 1.8 Å
Organism: Homo sapiens
Chains: 4
Atoms: 10,164
Mol. weight: 146.17 kDa
Ligands: ARG
Released: 12 Aug 2026

Explore 9PDO in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9PDO contains 75 α-helices and 77 β-strands across 4 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 18 helices, 20 β-strands

Element	Residues	Length	Sheet
β-strand	2-16	15	1
α-helix	17-19	3
α-helix	20-32	13
α-helix	34-36	3
β-strand	41-46	6	1
β-strand	50-56	7	1
α-helix	57-60	4
β-strand	69-71	3	1
β-strand	76-81	6	1
β-strand	93	1	2
α-helix	94-97	4
α-helix	98-102	5
α-helix	103-107	5
β-strand	112-116	5	1
β-strand	121-126	6	1
α-helix	127-129	3
α-helix	130-137	8
β-strand	142-147	6	1
β-strand	150-153	4	1
α-helix	174-176	3
β-strand	177-178	2	1
β-strand	184-187	4	1
β-strand	188	1	3
α-helix	191-193	3
α-helix	195-197	3
α-helix	198-206	9
α-helix	211-213	3
β-strand	228-233	6	1
β-strand	236-242	7	1
α-helix	243-246	4
β-strand	255	1	3
β-strand	263-268	6	1
α-helix	280-290	11
β-strand	295	1	2
β-strand	296-299	4	1
β-strand	304-309	6	1
α-helix	310-312	3
α-helix	313-321	9

Chain B: 18 helices, 19 β-strands

Element	Residues	Length	Sheet
β-strand	2-15	14	4
α-helix	17-23	7
α-helix	24-32	9
α-helix	34-36	3
β-strand	41-46	6	4
β-strand	51-56	6	4
α-helix	57-60	4
β-strand	69-71	3	4
β-strand	76-82	7	4
β-strand	93	1	5
α-helix	94-97	4
α-helix	98-102	5
α-helix	103-107	5
β-strand	112-116	5	4
β-strand	121-126	6	4
α-helix	127-129	3
α-helix	130-137	8
β-strand	142-147	6	4
β-strand	150-153	4	4
α-helix	174-176	3
β-strand	177-178	2	4
β-strand	183-189	7	4
α-helix	191-193	3
α-helix	194-202	9
α-helix	203-207	5
β-strand	228-233	6	4
β-strand	236-242	7	4
α-helix	243-246	4
α-helix	250	1
β-strand	255	1	4
β-strand	263-268	6	4
α-helix	280-290	11
β-strand	295	1	5
β-strand	296-299	4	4
β-strand	304-309	6	4
α-helix	310-312	3
α-helix	313-320	8

Chain C: 20 helices, 20 β-strands

Element	Residues	Length	Sheet
β-strand	2-15	14	6
α-helix	17-23	7
α-helix	24-32	9
α-helix	34-36	3
β-strand	41-46	6	6
β-strand	51-56	6	6
α-helix	57-60	4
β-strand	69-71	3	6
β-strand	76-82	7	6
β-strand	93	1	7
α-helix	95-97	3
α-helix	98-102	5
α-helix	103-107	5
β-strand	112-116	5	6
β-strand	121-126	6	6
α-helix	127-129	3
α-helix	130-137	8
β-strand	142-147	6	6
β-strand	150-153	4	6
α-helix	166-168	3
α-helix	170-172	3
α-helix	174-176	3
β-strand	177-178	2	6
β-strand	184-187	4	6
β-strand	188	1	8
α-helix	191-193	3
α-helix	194-202	9
α-helix	203-207	5
β-strand	228-233	6	6
β-strand	236-242	7	6
α-helix	243-247	5
α-helix	250	1
β-strand	255	1	8
β-strand	263-268	6	6
α-helix	280-290	11
β-strand	295	1	7
β-strand	296-299	4	6
β-strand	304-309	6	6
α-helix	310-312	3
α-helix	313-321	9

Chain D: 19 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	2-15	14	9
α-helix	17-23	7
α-helix	24-32	9
α-helix	34-36	3
β-strand	41-46	6	9
β-strand	51-56	6	9
α-helix	57-60	4
β-strand	69-71	3	9
β-strand	76-82	7	9
α-helix	84-86	3
β-strand	88	1	9
α-helix	94-97	4
α-helix	98-102	5
α-helix	103-107	5
β-strand	112-116	5	9
β-strand	121-126	6	9
α-helix	127-129	3
α-helix	130-137	8
β-strand	142-147	6	9
β-strand	150-153	4	9
β-strand	177-178	2	9
α-helix	182-183	2
β-strand	184-188	5	9
α-helix	191-197	7
α-helix	198-202	5
α-helix	203-207	5
β-strand	228-233	6	9
β-strand	236-242	7	9
α-helix	243-246	4
α-helix	250	1
β-strand	255-256	2	9
β-strand	263-268	6	9
α-helix	280-290	11
β-strand	296-299	4	9
β-strand	304-309	6	9
α-helix	310-312	3
α-helix	313-321	9

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Cytosolic arginine sensor for mTORC1 subunit 1	A, B, C, D	protein	329	Homo sapiens	Q8WTX7 (AlphaFold model)

Sequence of entity 1 (A, B, C, D), FASTA

>9PDO_1 Cytosolic arginine sensor for mTORC1 subunit 1 (chains A, B, C, D)
MELHILEHRVRVLSVARPGLWLYTHPLIKLLFLPRRSRCKFFSLTETPEDYTLMVDEEGF
KELPPSEFLQVAEATWLVLNVSSHSGAAVQAAGVTKIARSVIAPLAEHHVSVLMLSTYQT
DFILVREQDLSVVIHTLAQEFDIYREVGGEPVPVTRDDSSNGFPRTQHGPSPTVHPIQSP
QNRFCVLTLDPETLPAIATTLIDVLFYSHSTPKEAASSSPEPSSITFFAFSLIEGYISIV
MDAETQKKFPSDLLLTSSSGELWRMVRIGGQPLGFDECGIVAQIAGPLAAADISAYYIST
FNFDHALVPEDGIGSVIEVLQRRQEGLAS

Ligands and cofactors

ID	Name	Formula	Copies
ARG	Arginine	C6 H15 N4 O2	4

Water and common crystallization additives (ACT) are not listed.

Primary citation

Structural basis for the dynamic regulation of mTORC1 by amino acids. Valenstein, M.L., Wranik, M., Lalgudi, P.V. et al. Nature (2025) 646:493-500. DOI 10.1038/s41586-025-09428-7 · PubMed

Other PDB entries of the same protein (UniProt Q8WTX7 (AlphaFold model), which also has an AlphaFold model), best resolution first:

5I2C 1.8 Å, Arginine-bound CASTOR1 from Homo sapiens
5GT7 2.05 Å, Crystal Structure of Arg-bound CASTOR1
5GV2 2.06 Å, Crystal structure of Arginine-bound CASTOR1 from Homo sapiens
5GS9 2.5 Å, Crystal structure of CASTOR1-arginine
5GT8 2.8 Å, Crystal Structure of apo-CASTOR1
9KP4 3.08 Å, Crystal structure of human CASTOR1 in apo form
9DX2 3.4 Å, Human GATOR2 complex - CASTOR1 bound state
9LWF 3.41 Å, Cryo-EM structure of dual sensor bound GATOR2 complex
9OTI 3.5 Å, GATOR2 complex bound to arginine sensor CASTOR1
9LVK 3.59 Å, Cryo-EM structure of CASTOR1 bound human GATOR2 complex

Browse structure collections

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