8UO5: Protein Phosphatase 2A B55 subunit

Protein Phosphatase 2A B55 subunit in complex with IER5. Determined by electron microscopy at 3.27 Å resolution. Released 26 Mar 2025.

Method: Electron microscopy
Resolution: 3.27 Å
Organism: Homo sapiens
Chains: 4
Atoms: 10,216
Mol. weight: 166.74 kDa
Ligands: ZN, FE
Released: 26 Mar 2025

Explore 8UO5 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

8UO5 contains 85 α-helices and 45 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: 60 helices, 0 β-strands

Element	Residues	Length
α-helix	13-19	7
α-helix	25-32	8
α-helix	36-41	6
α-helix	63-73	11
α-helix	76-79	4
α-helix	82-85	4
α-helix	86-89	4
α-helix	90-97	8
α-helix	102-116	15
α-helix	121-123	3
α-helix	124-128	5
α-helix	129-137	9
α-helix	141-147	7
α-helix	151-154	4
α-helix	155-157	3
α-helix	160-174	15
α-helix	179-195	17
α-helix	198-200	3
α-helix	201-205	5
α-helix	206-212	7
α-helix	218-221	4
α-helix	224-234	11
α-helix	237-243	7
α-helix	245-252	8
α-helix	257-265	9
α-helix	267-278	12
α-helix	279-283	5
α-helix	284-291	8
α-helix	296-304	9
α-helix	306-312	7
α-helix	315-321	7
α-helix	322-326	5
α-helix	327-334	8
α-helix	339-349	11
α-helix	350-352	3
α-helix	353-356	4
α-helix	360	1
α-helix	361-365	5
α-helix	366-372	7
α-helix	378-385	8
α-helix	389-392	4
α-helix	398-411	14
α-helix	417-438	22
α-helix	439-443	5
α-helix	444-451	8
α-helix	456-473	18
α-helix	475-477	3
α-helix	478-482	5
α-helix	483-486	4
α-helix	487-491	5
α-helix	495-516	22
α-helix	517-521	5
α-helix	523-527	5
α-helix	528-530	3
α-helix	534-547	14
α-helix	548-550	3
α-helix	553-555	3
α-helix	556-560	5
α-helix	561-567	7
α-helix	573-586	14

Chain B: 10 helices, 30 β-strands

Element	Residues	Length	Sheet
α-helix	12	1
β-strand	13	1	1
α-helix	14-16	3
β-strand	17	1	2
β-strand	34-36	3	3
β-strand	42-45	4	3
β-strand	51-56	6	3
α-helix	57-59	3
β-strand	72-78	7	3
β-strand	98-101	4	4
α-helix	102-103	2
β-strand	109-114	6	4
β-strand	119-126	8	4
α-helix	130-135	6
α-helix	150-156	7
β-strand	164-171	8	4
β-strand	180-185	6	5
β-strand	191-196	6	5
β-strand	199-204	6	5
β-strand	212-216	5	5
α-helix	222-224	3
β-strand	232-234	3	6
β-strand	241-244	4	6
β-strand	251-255	5	6
β-strand	267-269	3	6
α-helix	282-285	4
β-strand	288-293	6	7
β-strand	299-304	6	7
β-strand	307-312	6	7
β-strand	321-324	4	7
α-helix	335-338	4
α-helix	341-343	3
β-strand	348-350	3	8
β-strand	356-361	6	8
β-strand	365-370	6	8
β-strand	376-380	5	8
β-strand	421-424	4	2
β-strand	431-434	4	2
β-strand	439-442	4	2
β-strand	443	1	1

Chain C: 13 helices, 15 β-strands

Element	Residues	Length	Sheet
α-helix	5-18	14
α-helix	21-24	4
α-helix	25-33	9
α-helix	47-49	3
β-strand	52-55	4	9
β-strand	57	1	10
α-helix	62-72	11
β-strand	80-84	5	9
α-helix	93-106	14
β-strand	111-116	6	9
α-helix	122-126	5
α-helix	129-136	8
α-helix	140-148	9
β-strand	156-157	2	11
β-strand	164-166	3	11
α-helix	177-182	6
α-helix	194-200	7
β-strand	202-203	2	12
β-strand	219-220	2	12
α-helix	222-230	9
β-strand	237-239	3	11
β-strand	247	1	9
β-strand	248-251	4	11
β-strand	256-259	4	11
β-strand	260	1	10
β-strand	273-278	6	9
β-strand	284-289	6	9
α-helix	290-292	3

Chain D: 2 helices, 0 β-strands

Element	Residues	Length	Sheet
α-helix	8-21	14
α-helix	30-38	9

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform	A	protein	613	Homo sapiens	P30153 (AlphaFold model)
Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform	B	protein	447	Homo sapiens	P63151 (AlphaFold model)
Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform	C	protein	332	Homo sapiens	P67775 (AlphaFold model)
Immediate early response gene 5 protein	D	protein	74	Homo sapiens	Q5VY09 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>8UO5_1 Serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (chains A)
MGSSHHHHHHSAVDENLYFQGGGRMAAADGDDSLYPIAVLIDELRNEDVQLRLNSIKKLS
TIALALGVERTRSELLPFLTDTIYDEDEVLLALAEQLGTFTTLVGGPEYVHCLLPPLESL
ATVEETVVRDKAVESLRAISHEHSPSDLEAHFVPLVKRLAGGDWFTSRTSACGLFSVCYP
RVSSAVKAELRQYFRNLCSDDTPMVRRAAASKLGEFAKVLELDNVKSEIIPMFSNLASDE
QDSVRLLAVEACVNIAQLLPQEDLEALVMPTLRQAAEDKSWRVRYMVADKFTELQKAVGP
EITKTDLVPAFQNLMKDCEAEVRAAASHKVKEFCENLSADCRENVIMSQILPCIKELVSD
ANQHVKSALASVIMGLSPILGKDNTIEHLLPLFLAQLKDECPEVRLNIISNLDCVNEVIG
IRQLSQSLLPAIVELAEDAKWRVRLAIIEYMPLLAGQLGVEFFDEKLNSLCMAWLVDHVY
AIREAATSNLKKLVEKFGKEWAHATIIPKVLAMSGDPNYLHRMTTLFCINVLSEVCGQDI
TTKHMLPTVLRMAGDPVANVRFNVAKSLQKIGPILDNSTLQSEVKPILEKLTQDQDVDVK
YFAQEALTVLSLA

Sequence of entity 2 (B), FASTA

>8UO5_2 Serine/threonine-protein phosphatase 2A 55 kDa regulatory subunit B alpha isoform (chains B)
MAGAGGGNDIQWCFSQVKGAVDDDVAEADIISTVEFNHSGELLATGDKGGRVVIFQQEQE
NKIQSHSRGEYNVYSTFQSHEPEFDYLKSLEIEEKINKIRWLPQKNAAQFLLSTNDKTIK
LWKISERDKRPEGYNLKEEDGRYRDPTTVTTLRVPVFRPMDLMVEASPRRIFANAHTYHI
NSISINSDYETYLSADDLRINLWHLEITDRSFNIVDIKPANMEELTEVITAAEFHPNSCN
TFVYSSSKGTIRLCDMRASALCDRHSKLFEEPEDPSNRSFFSEIISSISDVKFSHSGRYM
MTRDYLSVKIWDLNMENRPVETYQVHEYLRSKLCSLYENDCIFDKFECCWNGSDSVVMTG
SYNNFFRMFDRNTKRDITLEASRENNKPRTVLKPRKVCASGKRKKDEISVDSLDFNKKIL
HTAWHPKENIIAVATTNNLYIFQDKVN

Sequence of entity 3 (C), FASTA

>8UO5_3 Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform (chains C)
MDYKDDDDKSAVDENLYFQGGGRMDEKVFTKELDQWIEQLNECKQLSESQVKSLCEKAKE
ILTKESNVQEVRCPVTVCGDVHGQFHDLMELFRIGGKSPDTNYLFMGDYVDRGYYSVETV
TLLVALKVRYRERITILRGNHESRQITQVYGFYDECLRKYGNANVWKYFTDLFDYLPLTA
LVDGQIFCLHGGLSPSIDTLDHIRALDRLQEVPHEGPMCDLLWSDPDDRGGWGISPRGAG
YTFGQDISETFNHANGLTLVSRAHQLVMEGYNWCHDRNVVTIFSAPNYCYRCGNQAAIME
LDDTLKYSFLQFDPAPRRGEPHVTRRTPDYFL

Sequence of entity 4 (D), FASTA

>8UO5_4 Immediate early response gene 5 protein (chains D)
MDWSHPQFEKSAVDENLYFQGGGRMEFKLEAHRIVSISLGKIYNSRVQRGGIKLHKNLLV
SLVLRSARQVYLSD

Ligands and cofactors

ID	Name	Formula	Copies
ZN	Zinc ion	Zn	1
FE	FE (III) ion	Fe	1

Primary citation

Molecular mechanism of PP2A/B55 alpha phosphatase inhibition by IER5. Cao, R., Jones, D.T.D., Pan, L. et al. Cell Chem Biol (2025) 32:631-642.e7. DOI 10.1016/j.chembiol.2025.03.004 · PubMed

Other PDB entries of the same protein (UniProt P30153 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1B3U 2.3 Å, Crystal structure of constant regulatory domain of human PP2A, PR65ALPHA
4I5L 2.43 Å, Structural mechanism of trimeric PP2A holoenzyme involving PR70: insight for Cdc6…
8TWE 2.55 Å, Cryo-EM structure of the PP2A:B55-FAM122A complex, B55 body
2IE4 2.6 Å, Structure of the Protein Phosphatase 2A Core Enzyme Bound to okadaic acid
9C6B 2.6 Å, PP2A:B55-p107 substrate complex
8TWI 2.69 Å, Cryo-EM structure of the PP2A:B55-FAM122A complex, PP2Ac body
8U1X 2.7 Å, The structure of the PP2A-B56Delta holoenzyme mutant - E197K
9C7T 2.7 Å, PP2A:B55-Eya3 substrate complex
8TTB 2.77 Å, Cryo-EM structure of the PP2A:B55-ARPP19 complex
8SO0 2.8 Å, Cryo-EM structure of the PP2A:B55-FAM122A complex
2IE3 2.8 Å, Structure of the Protein Phosphatase 2A Core Enzyme Bound to Tumor-inducing Toxins
3C5W 2.8 Å, Complex between PP2A-specific methylesterase PME-1 and PP2A core enzyme

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