9MIP: PDB entry 9MIP

CryoEM structure of the Protein Phasphatase 2A (Aalpha-B56gamma-Calpha) holoenzyme complex. Determined by electron microscopy at 3.4 Å resolution. Released 9 Jul 2025.

Method: Electron microscopy
Resolution: 3.4 Å
Organism: Homo sapiens
Chains: 3
Atoms: 10,549
Mol. weight: 162.27 kDa
Ligands: MN
Released: 9 Jul 2025

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

Secondary structure: helices and β-sheets

9MIP contains 97 α-helices and 14 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: 53 helices, 0 β-strands

Element	Residues	Length
α-helix	10-21	12
α-helix	25-33	9
α-helix	35-58	24
α-helix	63-74	12
α-helix	83-86	4
α-helix	87-89	3
α-helix	90-97	8
α-helix	102-116	15
α-helix	121-123	3
α-helix	124-128	5
α-helix	129-136	8
α-helix	141-148	8
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	206-213	8
α-helix	218-234	17
α-helix	237-243	7
α-helix	245-252	8
α-helix	257-265	9
α-helix	267-274	8
α-helix	276-291	16
α-helix	296-311	16
α-helix	318-321	4
α-helix	322-326	5
α-helix	327-334	8
α-helix	339-349	11
α-helix	352-355	4
α-helix	358-360	3
α-helix	361-365	5
α-helix	366-374	9
α-helix	378-386	9
α-helix	391-394	4
α-helix	397-411	15
α-helix	417-434	18
α-helix	436-438	3
α-helix	439-443	5
α-helix	444-451	8
α-helix	456-473	18
α-helix	475-481	7
α-helix	483-488	6
α-helix	489-491	3
α-helix	495-516	22
α-helix	517-521	5
α-helix	522-528	7
α-helix	534-547	14
α-helix	553-555	3
α-helix	556-560	5
α-helix	561-568	8
α-helix	573-586	14

Chain B: 29 helices, 0 β-strands

Element	Residues	Length
α-helix	23-26	4
α-helix	38-48	11
α-helix	63-79	17
α-helix	91-103	13
α-helix	106-109	4
α-helix	124-125	2
α-helix	131-146	16
α-helix	152-156	5
α-helix	161-169	9
α-helix	170-172	3
α-helix	176-192	17
α-helix	197-210	14
α-helix	211-215	5
α-helix	221-233	13
α-helix	238-240	3
α-helix	241-246	6
α-helix	247-251	5
α-helix	252-256	5
α-helix	260-277	18
α-helix	279-281	3
α-helix	282-291	10
α-helix	298-314	17
α-helix	317-335	19
α-helix	340-347	8
α-helix	348-350	3
α-helix	353-376	24
α-helix	384-400	17
α-helix	402-431	30
α-helix	432-436	5

Chain C: 15 helices, 14 β-strands

Element	Residues	Length	Sheet
α-helix	4-18	15
α-helix	22-24	3
α-helix	25-39	15
β-strand	47-48	2	1
β-strand	53-55	3	2
α-helix	62-71	10
β-strand	80-83	4	2
α-helix	93-105	13
β-strand	111-114	4	2
α-helix	117-119	3
α-helix	121-126	6
α-helix	130-137	8
α-helix	141-151	11
β-strand	156-159	4	1
β-strand	163-166	4	1
α-helix	177-182	6
α-helix	188-190	3
α-helix	194-198	5
β-strand	203	1	3
β-strand	209	1	3
β-strand	220	1	3
α-helix	222-232	11
β-strand	236-239	4	1
β-strand	248-250	3	1
β-strand	256-259	4	1
α-helix	265-267	3
α-helix	271-272	2
β-strand	273-278	6	2
β-strand	284-289	6	2

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform	A	protein	589	Homo sapiens	P30153 (AlphaFold model)
Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform	B	protein	524	Homo sapiens	Q13362 (AlphaFold model)
Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform	C	protein	309	Homo sapiens	P67775 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>9MIP_1 Serine/threonine-protein phosphatase 2A 65 kDa regulatory subunit A alpha isoform (chains A)
MAAADGDDSLYPIAVLIDELRNEDVQLRLNSIKKLSTIALALGVERTRSELLPFLTDTIY
DEDEVLLALAEQLGTFTTLVGGPEYVHCLLPPLESLATVEETVVRDKAVESLRAISHEHS
PSDLEAHFVPLVKRLAGGDWFTSRTSACGLFSVCYPRVSSAVKAELRQYFRNLCSDDTPM
VRRAAASKLGEFAKVLELDNVKSEIIPMFSNLASDEQDSVRLLAVEACVNIAQLLPQEDL
EALVMPTLRQAAEDKSWRVRYMVADKFTELQKAVGPEITKTDLVPAFQNLMKDCEAEVRA
AASHKVKEFCENLSADCRENVIMSQILPCIKELVSDANQHVKSALASVIMGLSPILGKDN
TIEHLLPLFLAQLKDECPEVRLNIISNLDCVNEVIGIRQLSQSLLPAIVELAEDAKWRVR
LAIIEYMPLLAGQLGVEFFDEKLNSLCMAWLVDHVYAIREAATSNLKKLVEKFGKEWAHA
TIIPKVLAMSGDPNYLHRMTTLFCINVLSEVCGQDITTKHMLPTVLRMAGDPVANVRFNV
AKSLQKIGPILDNSTLQSEVKPILEKLTQDQDVDVKYFAQEALTVLSLA

Sequence of entity 2 (B), FASTA

>9MIP_2 Serine/threonine-protein phosphatase 2A 56 kDa regulatory subunit gamma isoform (chains B)
MLTCNKAGSRMVVDAANSNGPFQPVVLLHIRDVPPADQEKLFIQKLRQCCVLFDFVSDPL
SDLKWKEVKRAALSEMVEYITHNRNVITEPIYPEVVHMFAVNMFRTLPPSSNPTGAEFDP
EEDEPTLEAAWPHLQLVYEFFLRFLESPDFQPNIAKKYIDQKFVLQLLELFDSEDPRERD
FLKTTLHRIYGKFLGLRAYIRKQINNIFYRFIYETEHHNGIAELLEILGSIINGFALPLK
EEHKIFLLKVLLPLHKVKSLSVYHPQLAYCVVQFLEKDSTLTEPVVMALLKYWPKTHSPK
EVMFLNELEEILDVIEPSEFVKIMEPLFRQLAKCVSSPHFQVAERALYYWNNEYIMSLIS
DNAAKILPIMFPSLYRNSKTHWNKTIHGLIYNALKLFMEMNQKLFDDCTQQFKAEKLKEK
LKMKEREEAWVKIENLAKANPQYTVYSQASTMSIPVAMETDGPLFEDVQMLRKTVKDEAH
QAQKDPKKDRPLARRKSELPQDPHTKKALEAHCRADELASQDGR

Sequence of entity 3 (C), FASTA

>9MIP_3 Serine/threonine-protein phosphatase 2A catalytic subunit alpha isoform (chains C)
MDEKVFTKELDQWIEQLNECKQLSESQVKSLCEKAKEILTKESNVQEVRCPVTVCGDVHG
QFHDLMELFRIGGKSPDTNYLFMGDYVDRGYYSVETVTLLVALKVRYRERITILRGNHES
RQITQVYGFYDECLRKYGNANVWKYFTDLFDYLPLTALVDGQIFCLHGGLSPSIDTLDHI
RALDRLQEVPHEGPMCDLLWSDPDDRGGWGISPRGAGYTFGQDISETFNHANGLTLVSRA
HQLVMEGYNWCHDRNVVTIFSAPNYCYRCGNQAAIMELDDTLKYSFLQFDPAPRRGEPHV
TRRTPDYFL

Ligands and cofactors

ID	Name	Formula	Copies
MN	Manganese (II) ion	Mn	2

Primary citation

Regulatory mechanisms of PP2A complex assembly driven by physicochemical differences in A-subunit isoforms. Day, A., Huang, W., Leonard, D. et al. Structure (2025) 33:1688-1699.e5. DOI 10.1016/j.str.2025.06.013 · 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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