9SQK: Crystal structure hASF1A 156-cr17

Crystal structure hASF1A 156-cr17. Determined by X-ray diffraction at 1.7 Å resolution. Released 2 Sept 2026.

Method: X-ray diffraction
Resolution: 1.7 Å
Organism: Homo sapiens
Chains: 8
Atoms: 6,889
Mol. weight: 81.11 kDa
Released: 2 Sept 2026

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

Secondary structure: helices and β-sheets

9SQK contains 35 α-helices and 44 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.

Chain A: 8 helices, 10 β-strands

Element	Residues	Length	Sheet
β-strand	4-12	9	1
β-strand	16-17	2	2
α-helix	21	1
β-strand	22-30	9	1
β-strand	38-45	8	2
α-helix	51-53	3
β-strand	54-62	9	2
α-helix	64-66	3
β-strand	68-76	9	1
α-helix	77-79	3
α-helix	81-83	3
α-helix	86-89	4
β-strand	91-101	11	2
β-strand	104-117	14	2
α-helix	120-124	5
α-helix	132-134	3
β-strand	135-139	5	2
β-strand	145-148	4	2

Chain B: 8 helices, 10 β-strands

Element	Residues	Length	Sheet
β-strand	4-12	9	3
β-strand	16-17	2	4
α-helix	21	1
β-strand	22-30	9	3
β-strand	38-45	8	4
α-helix	51-53	3
β-strand	54-62	9	4
α-helix	65-66	2
β-strand	68-76	9	3
α-helix	77-79	3
α-helix	81-83	3
α-helix	86-89	4
β-strand	91-101	11	4
β-strand	104-117	14	4
α-helix	120-124	5
α-helix	132-134	3
β-strand	135-139	5	4
β-strand	145-148	4	4

Chain C: 7 helices, 10 β-strands

Element	Residues	Length	Sheet
β-strand	4-11	8	5
β-strand	16-17	2	6
α-helix	21	1
β-strand	22-30	9	5
β-strand	38-45	8	6
α-helix	51-53	3
β-strand	54-62	9	6
β-strand	68-76	9	5
α-helix	77-79	3
α-helix	81-83	3
α-helix	86-89	4
β-strand	91-101	11	6
β-strand	104-117	14	6
α-helix	120-124	5
α-helix	132-134	3
β-strand	135-139	5	6
β-strand	145-148	4	6

Chain D: 8 helices, 10 β-strands

Element	Residues	Length	Sheet
β-strand	4-11	8	7
β-strand	16-17	2	8
α-helix	21	1
β-strand	22-30	9	7
β-strand	38-45	8	8
α-helix	51-53	3
β-strand	54-62	9	8
α-helix	64-66	3
β-strand	68-76	9	7
α-helix	77-79	3
α-helix	81-83	3
α-helix	86-89	4
β-strand	91-101	11	8
β-strand	104-117	14	8
α-helix	120-124	5
α-helix	132-134	3
β-strand	135-139	5	8
β-strand	145-148	4	8

Chains E, G and H: 1 helix, 1 β-strand

Element	Residues	Length	Sheet
α-helix	3-6	4
β-strand	13	1	2

Chain F: 1 helix, 1 β-strand

Element	Residues	Length	Sheet
α-helix	2-6	5
β-strand	13	1	6

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Histone chaperone ASF1A	A, B, C, D	protein	157	Homo sapiens	Q9Y294 (AlphaFold model)
cr17	E, F, G, H	protein	18	Homo sapiens

Sequence of entity 1 (A, B, C, D), FASTA

>9SQK_1 Histone chaperone ASF1A (chains A, B, C, D)
GAMAKVQVNNVVVLDNPSPFYNPFQFEITFECIEDLSEDLEWKIIYVGSAESEEYDQVLD
SVLVGPVPAGRHMFVFQADAPNPGLIPDADAVGVTVVLITCTYRGQEFIRVGYYVNNEYT
ETELRENPPVKPDFSKLQRNILASNPRVTRFHINWED

Sequence of entity 2 (E, F, G, H), FASTA

>9SQK_2 cr17 (chains E, F, G, H)
XRKXXXXRIXXXVTTXXX

Primary citation

Downsizing the Histone H3-H4 Quaternary Structure Into Foldamer Mimetics Yields High-Affinity and Cell-Permeable Ligands of ASF1. Li, B., Perrin, M.E., Maillard, E. et al. Angew Chem Int Ed Engl (2026):e4112426-e4112426. DOI 10.1002/anie.4112426 · PubMed

Other PDB entries of the same protein (UniProt Q9Y294 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9SVO 1.6 Å, Crystal structure hASF1A 156-cr5
9TRB 1.65 Å, Crystal structure hASF1A 156-cr13
6ZUF 1.8 Å, Urea-based Foldamer Inhibitor chimera C2 in complex with ASF1 Histone chaperone
6F0H 1.98 Å, Crystal structure ASF1-ip4
9SS3 2.0 Å, Crystal structure hASF1A 156-cr7
6F0F 2.0 Å, Crystal structure ASF1-ip2_s
7LNY 2.1 Å, Apo structure of the Histone chaperone ASF1A residues 1-155
8CJ2 2.13 Å, Urea-based foldamer inhibitor c3u_5 chimera in complex with ASF1 histone chaperone
6F0G 2.3 Å, Crystal structure ASF1-ip3
8CJ1 2.56 Å, Urea-based foldamer inhibitor c3u_3 chimera in complex with ASF1 histone chaperone
2I32 2.7 Å, Structure of a human ASF1a-HIRA complex and insights into specificity of histone…
2IO5 2.7 Å, Crystal structure of the CIA- histone H3-H4 complex

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