9NXN: CN:RII alpha

Crystal structure of CN:RII alpha. Determined by X-ray diffraction at 2.1 Å resolution. Released 17 Dec 2025.

Method: X-ray diffraction
Resolution: 2.1 Å
Organism: Homo sapiens
Chains: 3
Atoms: 4,670
Mol. weight: 69.05 kDa
Ligands: CA
Released: 17 Dec 2025

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

Secondary structure: helices and β-sheets

9NXN contains 30 α-helices and 26 β-strands across 3 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: 19 helices, 22 β-strands

Element	Residues	Length	Sheet
α-helix	22-25	4
β-strand	29	1	1
α-helix	31-34	4
β-strand	35	1	2
β-strand	41	1	2
α-helix	43-51	9
β-strand	56	1	1
α-helix	58-73	16
β-strand	78-81	4	3
α-helix	82	1
β-strand	85-88	4	4
α-helix	95-105	11
β-strand	113-115	3	4
α-helix	126-139	14
β-strand	144-146	3	4
α-helix	154-159	6
α-helix	162-169	8
α-helix	172-183	12
β-strand	188-191	4	3
β-strand	195-197	3	3
β-strand	203	1	5
β-strand	206	1	5
α-helix	210-213	4
α-helix	220-222	3
α-helix	226-232	7
β-strand	234-235	2	6
β-strand	248-250	3	6
β-strand	258-260	3	6
α-helix	262-271	10
β-strand	276-279	4	3
β-strand	288-290	3	3
α-helix	292	1
β-strand	293	1	7
α-helix	294	1
β-strand	300	1	7
β-strand	302-305	4	3
α-helix	311-313	3
β-strand	319-325	7	4
β-strand	328-334	7	4
α-helix	344-346	3
α-helix	349-369	21

Chain B: 10 helices, 4 β-strands

Element	Residues	Length	Sheet
α-helix	6-9	4
α-helix	16-29	14
β-strand	36-37	2	8
α-helix	39-42	4
α-helix	46-48	3
α-helix	54-61	8
β-strand	69-70	2	8
α-helix	71-79	9
α-helix	87-98	12
β-strand	105-106	2	9
α-helix	108-119	12
α-helix	125-139	15
β-strand	147-148	2	9
α-helix	149-156	8

Chain C: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	86-88	3

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform	A	protein	370	Homo sapiens	Q08209 (AlphaFold model)
Calcineurin subunit B type 1	B	protein	170	Homo sapiens	P63098 (AlphaFold model)
cAMP-dependent protein kinase type II-alpha regulatory subunit	C	protein	64	Homo sapiens	P13861 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>9NXN_1 Serine/threonine-protein phosphatase 2B catalytic subunit alpha isoform (chains A)
MSEPKAIDPKLSTTDRVVKAVPFPPSHRLTAKEVFDNDGKPRVDILKAHLMKEGRLEESV
ALRIITEGASILRQEKNLLDIDAPVTVCGDIHGQFFDLMKLFEVGGSPANTRYLFLGDYV
DRGYFSIECVLYLWALKILYPKTLFLLRGNHECRHLTEYFTFKQECKIKYSERVYDACMD
AFDCLPLAALMNQQFLCVHGGLSPEINTLDDIRKLDRFKEPPAYGPMCDILWSDPLEDFG
NEKTQEHFTHNTVRGCSYFYSYPAVCEFLQHNNLLSILRAHEAQDAGYRMYRKSQTTGFP
SLITIFSAPNYLDVYNNKAAVLKYENNVMNIRQFNCSPHPYWLPNFMDVFTWSLPFVGEK
VTEMLVNVLN

Sequence of entity 2 (B), FASTA

>9NXN_2 Calcineurin subunit B type 1 (chains B)
MGNEASYPLEMCSHFDADEIKRLGKRFKKLDLDNSGSLSVEEFMSLPELQQNPLVQRVID
IFDTDGNGEVDFKEFIEGVSQFSVKGDKEQKLRFAFRIYDMDKDGYISNGELFQVLKMMV
GNNLKDTQLQQIVDKTIINADKDGDGRISFEEFCAVVGGLDIHKKMVVDV

Sequence of entity 3 (C), FASTA

>9NXN_3 cAMP-dependent protein kinase type II-alpha regulatory subunit (chains C)
GHMWRAPASVLPAATPRQSLGHPPPEPGPDRVADAKGDSESEEDEDLEVPVPSRFNRRVS
VCAE

Ligands and cofactors

ID	Name	Formula	Copies
CA	Calcium ion	Ca	4

Primary citation

The clinical missense variant E282K in PPP3CA/calcineurin shifts substrate dephosphorylation by altering active site recruitment. Shirakawa, K.T., Parikh, T., Machado, L.E.S.F. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-69535-5 · PubMed

Other PDB entries of the same protein (UniProt Q08209 (AlphaFold model), which also has an AlphaFold model), best resolution first:

2W73 1.45 Å, High-resolution structure of the complex between calmodulin and a peptide from…
4F0Z 1.7 Å, Crystal Structure of Calcineurin in Complex with the Calcineurin-Inhibiting Domain of…
6UUQ 1.85 Å, Structure of Calcineurin bound to RCAN1
2R28 1.86 Å, The complex Structure of Calmodulin Bound to a Calcineurin Peptide
6NUC 1.9 Å, Structure of Calcineurin in complex with NHE1 peptide
6NUF 1.9 Å, Structure of Calcineurin in complex with NHE1 peptide
4Q5U 1.95 Å, Structure of calmodulin bound to its recognition site from calcineurin
3LL8 2.0 Å, Crystal Structure of Calcineurin in Complex with AKAP79 Peptide
9NXE 2.09 Å, Crystal Structure of Calcineurin Clinical Variant E282K
1AUI 2.1 Å, Human calcineurin heterodimer
2P6B 2.3 Å, Crystal Structure of Human Calcineurin in Complex with PVIVIT Peptide
6NUU 2.3 Å, Structure of Calcineurin mutant in complex with NHE1 peptide

Browse structure collections

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