9KYS: The Ca2+/CaM-CASK-ARD complex

the Ca2+/CaM-CASK-ARD complex. Determined by X-ray diffraction at 1.76 Å resolution. Released 12 Nov 2025.

Method: X-ray diffraction
Resolution: 1.76 Å
Organisms: Rattus norvegicus, Homo sapiens
Chains: 4
Atoms: 3,088
Mol. weight: 46.25 kDa
Ligands: CA
Released: 12 Nov 2025

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

Secondary structure: helices and β-sheets

9KYS contains 18 α-helices and 8 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.

Chains A and C: 8 helices, 4 β-strands

Element	Residues	Length	Sheet
α-helix	7-20	14
β-strand	27-28	2	1
α-helix	30-39	10
α-helix	46-56	11
β-strand	64-65	2	1
α-helix	66-74	9
α-helix	79-93	15
β-strand	100-101	2	2
α-helix	103-112	10
α-helix	119-129	11
β-strand	137-138	2	2
α-helix	139-146	8

Chains B and D: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	300-319	20

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Calmodulin-1	A, C	protein	153	Rattus norvegicus	P0DP29 (AlphaFold model)
Peripheral plasma membrane protein CASK	B, D	protein	52	Homo sapiens	O14936 (AlphaFold model)

Sequence of entity 1 (A, C), FASTA

>9KYS_1 Calmodulin-1 (chains A, C)
GPGSMADQLTEEQIAEFKEAFSLFDKDGDGTITTKELGTVMRSLGQNPTEAELQDMINEV
DADGNGTIDFPEFLTMMARKMKDTDSEEEIREAFRVFDKDGNGYISAAELRHVMTNLGEK
LTDEEVDEMIREADIDGDGQVNYEEFVQMMTAK

Sequence of entity 2 (B, D), FASTA

>9KYS_2 Peripheral plasma membrane protein CASK (chains B, D)
GPGSEFHLPETVEQLRKFNARRKLKGAVLAAVSSHKFNSFYGDPPEELPDFS

Ligands and cofactors

ID	Name	Formula	Copies
CA	Calcium ion	Ca	8

Primary citation

Structural basis for the Ca 2+ /CaM-mediated regulation of CASK-CaMK. Li, W., Wang, Y., Feng, W. Int J Biol Macromol (2025) 332:148495-148495. DOI 10.1016/j.ijbiomac.2025.148495 · PubMed

Other PDB entries of the same protein (UniProt P0DP29 (AlphaFold model), which also has an AlphaFold model), best resolution first:

2PQ3 1.3 Å, N-Terminal Calmodulin Zn-Trapped Intermediate
4J9Y 1.51 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
1G4Y 1.6 Å, 1.60 a crystal structure of the gating domain from small conductance potassium channel…
3B32 1.6 Å, Crystal Structure of Calcium-Saturated Calmodulin N-Terminal Domain Fragment, Residues…
4G28 1.63 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
4G27 1.65 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
4J9Z 1.66 Å, Calcium-calmodulin complexed with the calmodulin binding domain from a small conductance…
9M6G 1.7 Å, the crystal structure of the Ca2+/CaM-CASK-CaMK-Mint1-CID complex
6MBA 1.8 Å, Crystal Structure of Human Nav1.4 CTerminal Domain in Complex with apo Calmodulin
9M5Y 1.8 Å, the crystal structure of the Ca2+/CaM-CASK-CaMK complex
9U9D 1.8 Å, Bipartite Genetically Encoded Biosensor sG-GECO1
2HQW 1.9 Å, Crystal Structure of Ca2+/Calmodulin bound to NMDA Receptor NR1C1 peptide

Browse structure collections

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