9QFD: Fully cofilin-1-decorated actin filament

Cryo-EM structure of the fully cofilin-1-decorated actin filament (cofilactin). Determined by electron microscopy at 2.61 Å resolution. Released 8 Oct 2025.

Method: Electron microscopy
Resolution: 2.61 Å
Organism: Homo sapiens
Chains: 14
Atoms: 28,854
Mol. weight: 424.32 kDa
Ligands: MG, ADP
Released: 8 Oct 2025

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

Secondary structure: helices and β-sheets

9QFD contains 236 α-helices and 203 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.

Chain A: 26 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	1
β-strand	16-21	6	1
β-strand	29-32	4	1
β-strand	35-38	4	2
β-strand	53-54	2	2
α-helix	56-60	5
β-strand	65-68	4	2
α-helix	79-87	9
α-helix	88-93	6
β-strand	96	1	3
α-helix	98-100	3
β-strand	103-107	5	1
α-helix	113-125	13
β-strand	131-136	6	1
α-helix	137-144	8
β-strand	150-155	6	4
β-strand	160-166	7	4
β-strand	169-170	2	4
α-helix	172-174	3
β-strand	176-178	3	4
α-helix	182-192	11
α-helix	193-196	4
α-helix	203-216	14
α-helix	223-232	10
β-strand	238-241	4	5
β-strand	247-250	4	5
α-helix	253-256	4
α-helix	258-261	4
α-helix	264-267	4
α-helix	272-273	2
α-helix	274-283	10
α-helix	287-289	3
α-helix	290-294	5
β-strand	297-300	4	4
α-helix	302-304	3
α-helix	309-320	12
β-strand	329-330	2	4
α-helix	335-337	3
α-helix	338-347	10
α-helix	350-354	5
β-strand	357-358	2	1
α-helix	359-365	7
α-helix	366-368	3
α-helix	369-373	5

Chains B and C: 24 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	6
β-strand	16-21	6	6
β-strand	29-32	4	6
β-strand	35-38	4	7
β-strand	53-54	2	7
α-helix	56-60	5
β-strand	65-68	4	7
α-helix	79-87	9
α-helix	88-93	6
β-strand	96	1	8
α-helix	98-100	3
β-strand	103-107	5	6
α-helix	113-125	13
β-strand	131-136	6	6
α-helix	137-144	8
β-strand	150-155	6	9
β-strand	160-166	7	9
β-strand	169-170	2	9
α-helix	172-174	3
β-strand	176-178	3	9
α-helix	182-193	12
α-helix	194-196	3
α-helix	203-216	14
α-helix	223-232	10
β-strand	238-241	4	10
β-strand	247-250	4	10
α-helix	253-259	7
α-helix	264-267	4
α-helix	274-283	10
α-helix	287-289	3
α-helix	290-294	5
β-strand	297-300	4	9
α-helix	302-304	3
α-helix	309-320	12
β-strand	329-330	2	9
α-helix	335-337	3
α-helix	338-348	11
α-helix	350-354	5
β-strand	357-358	2	6
α-helix	359-365	7
α-helix	366-368	3
α-helix	369-373	5

Chain D: 24 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	16
β-strand	16-21	6	16
β-strand	29-32	4	16
β-strand	35-38	4	17
β-strand	53-54	2	17
α-helix	56-60	5
β-strand	65-68	4	17
α-helix	79-87	9
α-helix	88-93	6
β-strand	96	1	18
α-helix	98-100	3
β-strand	103-107	5	16
α-helix	113-125	13
β-strand	131-136	6	16
α-helix	137-144	8
β-strand	150-155	6	19
β-strand	160-166	7	19
β-strand	169-170	2	19
α-helix	172-174	3
β-strand	176-178	3	19
α-helix	182-192	11
α-helix	193-196	4
α-helix	203-216	14
α-helix	223-230	8
β-strand	238-241	4	20
β-strand	247-250	4	20
α-helix	253-259	7
α-helix	264-267	4
α-helix	274-283	10
α-helix	287-289	3
α-helix	290-294	5
β-strand	297-300	4	19
α-helix	302-304	3
α-helix	309-320	12
β-strand	329-330	2	19
α-helix	335-337	3
α-helix	338-347	10
α-helix	352-354	3
β-strand	357-358	2	16
α-helix	359-365	7
α-helix	366-368	3
α-helix	369-373	5

Chain E: 25 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	21
β-strand	16-21	6	21
β-strand	29-32	4	21
β-strand	35-38	4	22
β-strand	53-54	2	22
α-helix	56-60	5
β-strand	65-68	4	22
α-helix	79-87	9
α-helix	88-93	6
β-strand	96	1	23
α-helix	98-100	3
β-strand	103-107	5	21
α-helix	113-125	13
β-strand	131-136	6	21
α-helix	137-144	8
β-strand	150-155	6	24
β-strand	160-166	7	24
β-strand	169-170	2	24
α-helix	172-174	3
β-strand	176-178	3	24
α-helix	182-193	12
α-helix	194-196	3
α-helix	203-216	14
α-helix	223-232	10
β-strand	238-241	4	25
β-strand	247-250	4	25
α-helix	253-256	4
α-helix	258-261	4
α-helix	264-267	4
α-helix	274-283	10
α-helix	287-289	3
α-helix	290-294	5
β-strand	297-300	4	24
α-helix	302-304	3
α-helix	309-320	12
β-strand	329-330	2	24
α-helix	335-337	3
α-helix	338-347	10
α-helix	350-354	5
β-strand	357-358	2	21
α-helix	359-365	7
α-helix	366-368	3
α-helix	369-373	5

Chain F: 25 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	26
β-strand	16-21	6	26
β-strand	29-32	4	26
β-strand	35-38	4	27
β-strand	53-54	2	27
α-helix	56-60	5
β-strand	65-68	4	27
α-helix	79-87	9
α-helix	88-93	6
β-strand	96	1	28
α-helix	98-100	3
β-strand	103-107	5	26
α-helix	113-125	13
β-strand	131-136	6	26
α-helix	137-144	8
β-strand	150-155	6	29
β-strand	160-166	7	29
β-strand	169-170	2	29
α-helix	172-174	3
β-strand	176-178	3	29
α-helix	182-193	12
α-helix	194-196	3
α-helix	203-216	14
α-helix	223-232	10
β-strand	238-241	4	30
β-strand	247-250	4	30
α-helix	253-259	7
α-helix	264-267	4
α-helix	272-273	2
α-helix	274-283	10
α-helix	287-289	3
α-helix	290-294	5
β-strand	297-300	4	29
α-helix	302-304	3
α-helix	309-320	12
β-strand	329-330	2	29
α-helix	335-337	3
α-helix	338-347	10
α-helix	350-354	5
β-strand	357-358	2	26
α-helix	359-365	7
α-helix	366-369	4
α-helix	370-373	4

Chain G: 25 helices, 18 β-strands

Element	Residues	Length	Sheet
β-strand	8-12	5	31
β-strand	16-21	6	31
β-strand	29-32	4	31
β-strand	35-38	4	32
β-strand	53-54	2	32
α-helix	56-60	5
β-strand	65-68	4	32
α-helix	79-87	9
α-helix	88-93	6
β-strand	96	1	33
α-helix	98-100	3
β-strand	103-107	5	31
α-helix	113-125	13
β-strand	131-136	6	31
α-helix	137-144	8
β-strand	150-155	6	34
β-strand	160-166	7	34
β-strand	169-170	2	34
α-helix	172-174	3
β-strand	176-178	3	34
α-helix	182-192	11
α-helix	193-196	4
α-helix	203-216	14
α-helix	223-232	10
β-strand	238-241	4	35
β-strand	247-250	4	35
α-helix	253-256	4
α-helix	258-261	4
α-helix	264-267	4
α-helix	272-273	2
α-helix	274-283	10
α-helix	287-294	8
β-strand	297-300	4	34
α-helix	302-304	3
α-helix	309-320	12
α-helix	326-327	2
β-strand	329-330	2	34
α-helix	338-347	10
α-helix	350-354	5
β-strand	357-358	2	31
α-helix	359-365	7
α-helix	366-368	3
α-helix	369-373	5

Chain H: 9 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	6-7	2	36
α-helix	9-19	11
β-strand	21	1	3
α-helix	22-23	2
α-helix	26-30	5
β-strand	33-40	8	36
β-strand	46-56	11	36
β-strand	60	1	37
β-strand	64	1	37
α-helix	67-73	7
β-strand	81-91	11	36
β-strand	95-104	10	36
α-helix	111-119	9
α-helix	121-127	7
β-strand	133-137	5	36
α-helix	140-142	3
α-helix	146-154	9
α-helix	155-157	3
β-strand	158-161	4	36
β-strand	164-165	2	36

Chains I, J, K, L, M and N: 9 helices, 11 β-strands

Element	Residues	Length	Sheet
β-strand	6-7	2	38
α-helix	9-19	11
β-strand	21	1	8
α-helix	22-23	2
α-helix	26-29	4
β-strand	33-40	8	38
β-strand	46-56	11	38
β-strand	60	1	39
β-strand	64	1	39
α-helix	67-73	7
β-strand	81-91	11	38
β-strand	95-104	10	38
α-helix	111-119	9
α-helix	121-127	7
β-strand	133-137	5	38
α-helix	140-142	3
α-helix	146-154	9
α-helix	155-157	3
β-strand	158-161	4	38
β-strand	164-165	2	38

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Actin, cytoplasmic 1, N-terminally processed	A, B, C, D, E, F, G	protein	374	Homo sapiens	P60709 (AlphaFold model)
Cofilin-1	H, I, J, K, L, M, N	protein	166	Homo sapiens	P23528 (AlphaFold model)

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

>9QFD_1 Actin, cytoplasmic 1, N-terminally processed (chains A, B, C, D, E, F, G)
DDDIAALVVDNGSGMCKAGFAGDDAPRAVFPSIVGRPRHQGVMVGMGQKDSYVGDEAQSK
RGILTLKYPIEHGIVTNWDDMEKIWHHTFYNELRVAPEEHPVLLTEAPLNPKANREKMTQ
IMFETFNTPAMYVAIQAVLSLYASGRTTGIVMDSGDGVTHTVPIYEGYALPHAILRLDLA
GRDLTDYLMKILTERGYSFTTTAEREIVRDIKEKLCYVALDFEQEMATAASSSSLEKSYE
LPDGQVITIGNERFRCPEALFQPSFLGMESAGIHETTFNSIMKCDVDIRKDLYANTVLSG
GTTMYPGIADRMQKEITALAPSTMKIKIIAPPERKYSVWIGGSILASLSTFQQMWISKQE
YDESGPSIVHRKCF

Sequence of entity 2 (H, I, J, K, L, M, N), FASTA

>9QFD_2 Cofilin-1 (chains H, I, J, K, L, M, N)
MASGVAVSDGVIKVFNDMKVRKSSTPEEVKKRKKAVLFCLSEDKKNIILEEGKEILVGDV
GQTVDDPYATFVKMLPDKDCRYALYDATYETKESKKEDLVFIFWAPESAPLKSKMIYASS
KDAIKKKLTGIKHELQANCYEEVKDRCTLAEKLGGSAVISLEGKPL

Ligands and cofactors

ID	Name	Formula	Copies
MG	Magnesium ion	Mg	7
ADP	Adenosine-5'-diphosphate	C10 H15 N5 O10 P2	7

Primary citation

Choreography of rapid actin filament disassembly by coronin, cofilin, and AIP1. Oosterheert, W., Boiero Sanders, M., Hofnagel, O. et al. Cell (2025) 188:6845. DOI 10.1016/j.cell.2025.09.016 · PubMed

Other PDB entries of the same protein (UniProt P60709 (AlphaFold model), which also has an AlphaFold model), best resolution first:

6MBK 1.69 Å, SETD3, a Histidine Methyltransferase, in Complex with an Actin Peptide and SAH, First…
6OX0 1.75 Å, SETD3 in Complex with an Actin Peptide with Sinefungin Replacing SAH as Cofactor
6MBJ 1.78 Å, SETD3, a Histidine Methyltransferase, in Complex with an Actin Peptide and SAH, P21…
6OX3 1.78 Å, SETD3 in Complex with an Actin Peptide with His73 Replaced with Lysine
7W28 1.79 Å, Crystal Structure of SETD3-SAH in complex with betaA-4PyrAla73 peptide
6OX1 1.95 Å, SETD3 in Complex with an Actin Peptide with Target Histidine Partially Methylated
6ICT 1.95 Å, Structure of SETD3 bound to SAH and methylated actin
6OX2 2.09 Å, SETD3in Complex with an Actin Peptide with the Target Histidine Fully Methylated
6OX5 2.1 Å, A SETD3 Mutant (N255A) in Complex with an Actin Peptide with His73 Replaced with Lysine
6ICV 2.15 Å, Structure of SETD3 bound to SAH and unmodified actin
9QEW 2.18 Å, Cryo-EM structure of the undecorated actin filament in the ADP-Pi state.
6MBL 2.2 Å, SETD3, a Histidine Methyltransferase, in Complex with an Actin Peptide and SAH, Second…

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