9MO9: Actin, alpha cardiac muscle 1

Structure of native murine cardiac thin filament variant I79N in troponin T at pCa=5.8 in Ca2+-free rotated state (lower strand). Determined by electron microscopy at 5.6 Å resolution. Released 28 May 2025.

Method
Electron microscopy
Resolution
5.6 Å
Organism
Mus musculus
Chains
14
Atoms
25,887
Mol. weight
498.11 kDa
Ligands
MG, ADP
Released
28 May 2025

Explore 9MO9 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9MO9 contains 155 α-helices and 128 β-strands across 14 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 and F: 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 E: 22 helices, 22 β-strands
ElementResiduesLengthSheet
α-helix6-72
β-strand8125
β-strand11126
β-strand17-19326
β-strand21125
β-strand24127
β-strand29-31326
β-strand35-38428
β-strand53-54228
α-helix55-595
α-helix62-643
β-strand65-68428
β-strand71129
β-strand76129
α-helix79-8810
α-helix89-946
α-helix98-1003
β-strand103-107525
α-helix113-12513
β-strand131-136625
α-helix137-1448
β-strand150-155630
β-strand160-166730
β-strand169-170230
α-helix172-1743
β-strand176-178330
α-helix182-19211
α-helix193-1953
α-helix205-21612
α-helix223-2308
β-strand238-242531
β-strand245-250631
α-helix258-2614
α-helix274-28310
α-helix290-2956
β-strand297-300430
α-helix302-3054
α-helix309-32012
β-strand329-330230
α-helix338-34710
α-helix351-3544
β-strand357-358225
α-helix359-3657
α-helix367-3693
Chain G: 9 helices, 0 β-strands
ElementResiduesLengthSheet
α-helix4-107
α-helix14-2714
α-helix38-4710
α-helix54-6310
α-helix74-8411
α-helix94-10411
α-helix114-12411
α-helix135-1406
α-helix150-1578
Chain H: 6 helices, 1 β-strand
ElementResiduesLengthSheet
α-helix47-8034
α-helix82-854
α-helix91-13747
α-helix138-1403
α-helix152-1543
α-helix158-18427
β-strand185127
Chain I: 3 helices, 0 β-strands
ElementResiduesLengthSheet
α-helix202-2098
α-helix210-2145
α-helix226-27146
Chain J: 1 helix, 0 β-strands
ElementResiduesLengthSheet
α-helix89-14961
Chain K: 1 helix, 0 β-strands
ElementResiduesLengthSheet
α-helix65-283219
Chain L: 1 helix, 0 β-strands
ElementResiduesLengthSheet
α-helix65-281217

1 more chain groups are not listed. Open the entry in the viewer and use the sequence panel to see them.

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
Actin, alpha cardiac muscle 1A, B, C, D, E, Fprotein377Mus musculusP68033 (AlphaFold model)
Troponin C, slow skeletal and cardiac musclesGprotein161Mus musculusP19123 (AlphaFold model)
Troponin I, cardiac muscleHprotein211Mus musculusP48787 (AlphaFold model)
Isoform 6 of Troponin T, cardiac muscleI, Jprotein288Mus musculusP45379 (AlphaFold model)
Tropomyosin alpha-1 chainK, L, M, Nprotein284Mus musculusP58771
Sequence of entity 1 (A, B, C, D, E, F), FASTA
>9MO9_1 Actin, alpha cardiac muscle 1 (chains A, B, C, D, E, F)
MCDDEETTALVCDNGSGLVKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEA
QSKRGILTLKYPIEHGIITNWDDMEKIWHHTFYNELRVAPEEHPTLLTEAPLNPKANREK
MTQIMFETFNVPAMYVAIQAVLSLYASGRTTGIVLDSGDGVTHNVPIYEGYALPHAIMRL
DLAGRDLTDYLMKILTERGYSFVTTAEREIVRDIKEKLCYVALDFENEMATAASSSSLEK
SYELPDGQVITIGNERFRCPETLFQPSFIGMESAGIHETTYNSIMKCDIDIRKDLYANNV
LSGGTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWIS
KQEYDEAGPSIVHRKCF
Sequence of entity 2 (G), FASTA
>9MO9_2 Troponin C, slow skeletal and cardiac muscles (chains G)
MDDIYKAAVEQLTEEQKNEFKAAFDIFVLGAEDGCISTKELGKVMRMLGQNPTPEELQEM
IDEVDEDGSGTVDFDEFLVMMVRCMKDDSKGKSEEELSDLFRMFDKNADGYIDLDELKMM
LQATGETITEDDIEELMKDGDKNNDGRIDYDEFLEFMKGVE
Sequence of entity 3 (H), FASTA
>9MO9_3 Troponin I, cardiac muscle (chains H)
MADESSDAAGEPQPAPAPVRRRSSANYRAYATEPHAKKKSKISASRKLQLKTLMLQIAKQ
EMEREAEERRGEKGRVLRTRCQPLELDGLGFEELQDLCRQLHARVDKVDEERYDVEAKVT
KNITEIADLTQKIYDLRGKFKRPTLRRVRISADAMMQALLGTRAKESLDLRAHLKQVKKE
DIEKENREVGDWRKNIDALSGMEGRKKKFEG
Sequence of entity 4 (I, J), FASTA
>9MO9_4 Isoform 6 of Troponin T, cardiac muscle (chains I, J)
MSDIEEVVEEYEEEEQEEAAVEEQEEAAEEDAEAEAETEETRAEEDEEEEEAKEAEDGPM
EESKPKPRSFMPNLVPPKNPDGERVDFDDIHRKRMEKDLNELQALIEAHFENRKKEEEEL
VSLKDRIERRRAERAEQQRIRNEREKERQNRLAEERARREEEENRRKAEDEARKKKALSN
MMHFGGYIQKQAQTERKSGKRQTEREKKKKILAERRKVLAIDHLNEDQLREKAKELWQSI
YNLEAEKFDLQEKFKQQKYEINVLRNRINDNQKVSKTRGKAKVTGRWK
Sequence of entity 5 (K, L, M, N), FASTA
>9MO9_5 Tropomyosin alpha-1 chain (chains K, L, M, N)
MDAIKKKMQMLKLDKENALDRAEQAEADKKAAEDRSKQLEDELVSLQKKLKGTEDELDKY
SEALKDAQEKLELAEKKATDAEADVASLNRRIQLVEEELDRAQERLATALQKLEEAEKAA
DESERGMKVIESRAQKDEEKMEIQEIQLKEAKHIAEDADRKYEEVARKLVIIESDLERAE
ERAELSEGKCAELEEELKTVTNNLKSLEAQAEKYSQKEDKYEEEIKVLSDKLKEAETRAE
FAERSVTKLEKSIDDLEDELYAQKLKYKAISEELDHALNDMTSI

Ligands and cofactors

IDNameFormulaCopies
MGMagnesium ionMg6
ADPAdenosine-5'-diphosphateC10 H15 N5 O10 P26

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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