9K44: Histone H3.3

Cryo-EM structure of Arabidopsis thaliana H2A-H3.3-nucleosome with Arabidopsis native 147bp DNA 15.2.2 (C2 symmetry). Determined by electron microscopy at 3.22 Å resolution. Released 12 Nov 2025.

Method
Electron microscopy
Resolution
3.22 Å
Organism
Arabidopsis thaliana
Chains
10
Atoms
11,840
Mol. weight
204.72 kDa
Released
12 Nov 2025

Explore 9K44 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9K44 contains 36 α-helices and 20 β-strands across 8 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 and E: 5 helices, 2 β-strands

ElementResiduesLengthSheet
α-helix41-422
α-helix45-5612
α-helix64-7512
β-strand83-8421
α-helix86-11328
β-strand118-11922
α-helix121-13111
Chain B: 4 helices, 3 β-strands
ElementResiduesLengthSheet
α-helix26-283
α-helix31-4010
β-strand45-4622
α-helix50-7526
β-strand80-8121
α-helix83-9210
β-strand97-9823
Chains C and G: 5 helices, 3 β-strands
ElementResiduesLengthSheet
α-helix18-214
α-helix28-3710
β-strand43-4424
α-helix48-7326
β-strand78-7925
α-helix81-9010
α-helix92-976
β-strand102-10326
Chain D: 4 helices, 2 β-strands
ElementResiduesLengthSheet
α-helix61-7111
β-strand76-7725
α-helix79-10628
β-strand111-11224
α-helix114-12411
α-helix127-14620
Chain F: 4 helices, 3 β-strands
ElementResiduesLengthSheet
α-helix25-284
α-helix31-4010
β-strand45-4628
α-helix50-7526
β-strand80-8127
α-helix83-9210
β-strand97-9826
Chain H: 4 helices, 2 β-strands
ElementResiduesLengthSheet
α-helix61-7111
β-strand76-77210
α-helix79-10628
β-strand111-11229
α-helix114-12411
α-helix127-14519

Molecules and chains

MoleculeChainsTypeLengthOrganismUniProt
Histone H3.3A, Eprotein136Arabidopsis thalianaP59169 (AlphaFold model)
Histone H4B, Fprotein103Arabidopsis thalianaP59259 (AlphaFold model)
Histone H2A.6C, Gprotein130Arabidopsis thalianaQ9LD28 (AlphaFold model)
Histone H2B.1D, Hprotein148Arabidopsis thalianaQ9LQQ4 (AlphaFold model)
15.2.2 DNA (147-mer)IDNA147Arabidopsis thaliana
15.2.2 DNA (147-mer)JDNA147Arabidopsis thaliana
Sequence of entity 1 (A, E), FASTA
>9K44_1 Histone H3.3 (chains A, E)
MARTKQTARKSTGGKAPRKQLATKAARKSAPTTGGVKKPHRYRPGTVALREIRKYQKSTE
LLIRKLPFQRLVREIAQDFKTDLRFQSHAVLALQEAAEAYLVGLFEDTNLCAIHAKRVTI
MPKDIQLARRIRGERA
Sequence of entity 2 (B, F), FASTA
>9K44_2 Histone H4 (chains B, F)
MSGRGKGGKGLGKGGAKRHRKVLRDNIQGITKPAIRRLARRGGVKRISGLIYEETRGVLK
IFLENVIRDAVTYTEHARRKTVTAMDVVYALKRQGRTLYGFGG
Sequence of entity 3 (C, G), FASTA
>9K44_3 Histone H2A.6 (chains C, G)
MAGRGKTLGSGGAKKATSRSSKAGLQFPVGRIARFLKAGKYAERVGAGAPVYLAAVLEYL
AAEVLELAGNAARDNKKTRIVPRHIQLAVRNDEELSKLLGDVTIANGGVMPNIHNLLLPK
KAGASKPQED
Sequence of entity 4 (D, H), FASTA
>9K44_4 Histone H2B.1 (chains D, H)
MAPRAEKKPAEKKTAAERPVEENKAAEKAPAEKKPKAGKKLPPKEAGDKKKKRSKKNVET
YKIYIFKVLKQVHPDIGISSKAMGIMNSFINDIFEKLAQESSKLARYNKKPTITSREIQT
AVRLVLPGELAKHAVSEGTKAVTKFTSS
Sequence of entity 5 (I), FASTA
>9K44_5 15.2.2 DNA (147-MER) (chains I)
ACCTTTATTGACTCCATAATTGACCAATTGAGCGGCTCGATTCAACTGTCAATAACTTCA
AATGAAGCAAGAGCCTTATCGTATTCTCCGCACGATGGTGCTTTAATCCACCGCAACTTT
CCTCTTTAATAAAGGCACAAGCATTAA
Sequence of entity 6 (J), FASTA
>9K44_6 15.2.2 DNA (147-MER) (chains J)
TTAATGCTTGTGCCTTTATTAAAGAGGAAAGTTGCGGTGGATTAAAGCACCATCGTGCGG
AGAATACGATAAGGCTCTTGCTTCATTTGAAGTTATTGACAGTTGAATCGAGCCGCTCAA
TTGGTCAATTATGGAGTCAATAAAGGT

Primary citation

Functional redundancy of core histone H2A and its variants in Arabidopsis. Wang, Y., Dong, A. To be published.

Other PDB entries of the same protein (UniProt P59169 (AlphaFold model), which also has an AlphaFold model), best resolution first:

Browse structure collections

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