9MOU: Actin, alpha cardiac muscle 1

Structure of native murine cardiac thin filament variant I79N in troponin T at pCa=5.8 in Ca2+-bound partially activated state (upper strand). Determined by electron microscopy at 5.6 Å resolution. Released 4 Jun 2025.

Method
Electron microscopy
Resolution
5.6 Å
Organism
Mus musculus
Chains
15
Atoms
28,660
Mol. weight
540.74 kDa
Ligands
CA, MG, ADP
Released
4 Jun 2025

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

Secondary structure: helices and β-sheets

9MOU contains 174 α-helices and 149 β-strands across 15 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, B, C, D, E, F and G: 22 helices, 21 β-strands

ElementResiduesLengthSheet
α-helix6-72
β-strand811
β-strand1112
β-strand17-1932
β-strand2111
β-strand29-3132
β-strand35-3843
β-strand53-5423
α-helix55-595
α-helix62-643
β-strand65-6843
β-strand7114
β-strand7614
α-helix79-8810
α-helix89-946
α-helix98-1003
β-strand103-10751
α-helix113-12513
β-strand131-13661
α-helix137-1448
β-strand150-15565
β-strand160-16675
β-strand169-17025
α-helix172-1743
β-strand176-17835
α-helix182-19211
α-helix193-1953
α-helix205-21612
α-helix223-2308
β-strand238-24256
β-strand245-25066
α-helix258-2614
α-helix274-28310
α-helix290-2956
β-strand297-30045
α-helix302-3054
α-helix309-32012
β-strand329-33025
α-helix338-34710
α-helix351-3544
β-strand357-35821
α-helix359-3657
α-helix367-3693
Chain H: 9 helices, 2 β-strands
ElementResiduesLengthSheet
α-helix3-108
α-helix15-2814
α-helix39-468
α-helix55-628
α-helix74-8411
α-helix94-10411
β-strand112143
α-helix114-12411
α-helix130-14011
β-strand148143
α-helix150-1567
Chain I: 4 helices, 0 β-strands
ElementResiduesLengthSheet
α-helix44-8037
α-helix91-13646
α-helix139-1413
α-helix152-1609
Chain J: 2 helices, 0 β-strands
ElementResiduesLengthSheet
α-helix201-21515
α-helix226-27146
Chain K: 1 helix, 0 β-strands
ElementResiduesLengthSheet
α-helix87-17488
Chains L and M: 1 helix, 0 β-strands
ElementResiduesLengthSheet
α-helix65-282218
Chains N and O: 1 helix, 0 β-strands
ElementResiduesLengthSheet
α-helix3-5452

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
Actin, alpha cardiac muscle 1A, B, C, D, E, F, Gprotein377Mus musculusP68033 (AlphaFold model)
Troponin C, slow skeletal and cardiac musclesHprotein161Mus musculusP19123 (AlphaFold model)
Troponin I, cardiac muscleIprotein211Mus musculusP48787 (AlphaFold model)
Isoform 6 of Troponin T, cardiac muscleJ, Kprotein288Mus musculusP45379 (AlphaFold model)
Tropomyosin alpha-1 chainL, M, N, Oprotein284Mus musculusP58771
Sequence of entity 1 (A, B, C, D, E, F, G), FASTA
>9MOU_1 Actin, alpha cardiac muscle 1 (chains A, B, C, D, E, F, G)
MCDDEETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEA
QSKRGILTLKYPIEHGIITNWDDMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREK
MTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSGDGVTHNVPIYEGYALPHAIMRL
DLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSLEK
SYELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNV
LSGGTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWIS
KQEYDEAGPSIVHRKCF
Sequence of entity 2 (H), FASTA
>9MOU_2 Troponin C, slow skeletal and cardiac muscles (chains H)
MDDIYKAAVEQLTEEQKNEFKAAFDIFVLGAEDGCISTKELGKVMRMLGQNPTPEELQEM
IDEVDEDGSGTVDFDEFLVMMVRCMKDDSKGKSEEELSDLFRMFDKNADGYIDLDELKMM
LQATGETITEDDIEELMKDGDKNNDGRIDYDEFLEFMKGVE
Sequence of entity 3 (I), FASTA
>9MOU_3 Troponin I, cardiac muscle (chains I)
MADESSDAAGEPQPAPAPVRRRSSANYRAYATEPHAKKKSKISASRKLQLKTLMLQIAKQ
EMEREAEERRGEKGRVLRTRCQPLELDGLGFEELQDLCRQLHARVDKVDEERYDVEAKVT
KNITEIADLTQKIYDLRGKFKRPTLRRVRISADAMMQALLGTRAKESLDLRAHLKQVKKE
DIEKENREVGDWRKNIDALSGMEGRKKKFEG
Sequence of entity 4 (J, K), FASTA
>9MOU_4 Isoform 6 of Troponin T, cardiac muscle (chains J, K)
MSDIEEVVEEYEEEEQEEAAVEEQEEAAEEDAEAEAETEETRAEEDEEEEEAKEAEDGPM
EESKPKPRSFMPNLVPPKNPDGERVDFDDIHRKRMEKDLNELQALIEAHFENRKKEEEEL
VSLKDRIERRRAERAEQQRIRNEREKERQNRLAEERARREEEENRRKAEDEARKKKALSN
MMHFGGYIQKQAQTERKSGKRQTEREKKKKILAERRKVLAIDHLNEDQLREKAKELWQSI
YNLEAEKFDLQEKFKQQKYEINVLRNRINDNQKVSKTRGKAKVTGRWK
Sequence of entity 5 (L, M, N, O), FASTA
>9MOU_5 Tropomyosin alpha-1 chain (chains L, M, N, O)
MDAIKKKMQMLKLDKENALDRAEQAEADKKAAEDRSKQLEDELVSLQKKLKGTEDELDKY
SEALKDAQEKLELAEKKATDAEADVASLNRRIQLVEEELDRAQERLATALQKLEEAEKAA
DESERGMKVIESRAQKDEEKMEIQEIQLKEAKHIAEDADRKYEEVARKLVIIESDLERAE
ERAELSEGKCAELEEELKTVTNNLKSLEAQAEKYSQKEDKYEEEIKVLSDKLKEAETRAE
FAERSVTKLEKSIDDLEDELYAQKLKYKAISEELDHALNDMTSI

Ligands and cofactors

IDNameFormulaCopies
CACalcium ionCa3
MGMagnesium ionMg7
ADPAdenosine-5'-diphosphateC10 H15 N5 O10 P27

Primary citation

The role of the troponin T interactions with actin in regulation of cardiac thin filament revealed by the troponin T pathogenic variant Ile79Asn. Risi, C.M., Landim-Vieira, M., Belknap, B. et al. J Mol Cell Cardiol (2025) 204:55-67. DOI 10.1016/j.yjmcc.2025.05.005 · PubMed

Other PDB entries of the same protein (UniProt P68033 (AlphaFold model), which also has an AlphaFold model), best resolution first:

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