23BB: Caspase-4 p20/p10 and human GSDMD

Caspase-4 p20/p10 and human GSDMD. Determined by electron microscopy at 3.6 Å resolution. Released 24 Jun 2026.

Method: Electron microscopy
Resolution: 3.6 Å
Organism: Homo sapiens
Chains: 5
Atoms: 6,957
Mol. weight: 111.75 kDa
Released: 24 Jun 2026

Explore 23BB in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

23BB contains 36 α-helices and 46 β-strands across 5 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: 18 helices, 16 β-strands

Element	Residues	Length	Sheet
α-helix	6-12	7
β-strand	23-24	2	11
β-strand	39-42	4	11
α-helix	43-45	3
β-strand	47	1	12
β-strand	50	1	12
α-helix	52-54	3
β-strand	55-56	2	11
β-strand	120-121	2	11
α-helix	127-136	10
α-helix	143-144	2
α-helix	145-153	9
β-strand	156-166	11	11
β-strand	213-222	10	11
β-strand	228-230	3	11
β-strand	272-274	3	10
β-strand	276	1	7
α-helix	277-278	2
α-helix	287-301	15
β-strand	304	1	8
α-helix	310-320	11
α-helix	323-336	14
α-helix	347-354	8
β-strand	357	1	13
β-strand	363	1	13
α-helix	365-380	16
α-helix	383-395	13
α-helix	399-409	11
α-helix	425-428	4
α-helix	437-445	9
β-strand	449	1	14
β-strand	456	1	14
α-helix	460-462	3
α-helix	463-479	17

Chain B: 7 helices, 9 β-strands

Element	Residues	Length	Sheet
α-helix	108-110	3
α-helix	111-120	10
β-strand	125	1	1
β-strand	136-142	7	2
α-helix	150-151	2
α-helix	156-168	13
β-strand	171-177	7	2
α-helix	181-192	12
α-helix	196-199	4
β-strand	203-208	6	2
β-strand	211	1	3
β-strand	215-217	3	3
β-strand	228-230	3	3
α-helix	231-238	8
β-strand	251-256	6	2
β-strand	265-268	4	4

Chain C: 3 helices, 6 β-strands

Element	Residues	Length	Sheet
β-strand	291-294	4	8
β-strand	300-304	5	2
α-helix	311-313	3
β-strand	314	1	9
β-strand	320	1	9
α-helix	321-333	13
α-helix	339-349	11
β-strand	361-365	5	2
β-strand	370	1	1

Chain D: 2 helices, 6 β-strands

Element	Residues	Length	Sheet
β-strand	292-295	4	4
β-strand	300-302	3	6
β-strand	303-304	2	2
β-strand	313-315	3	10
α-helix	321-332	12
α-helix	339-349	11
β-strand	361-365	5	2
β-strand	370	1	5

Chain E: 6 helices, 9 β-strands

Element	Residues	Length	Sheet
α-helix	106-110	5
α-helix	111-120	10
β-strand	125	1	5
β-strand	137-142	6	6
α-helix	155-168	14
β-strand	173-177	5	6
α-helix	181-192	12
α-helix	196-199	4
β-strand	203-208	6	6
β-strand	211-212	2	7
β-strand	215-217	3	7
β-strand	228-230	3	7
α-helix	231-238	8
β-strand	251-256	6	6
β-strand	266-269	4	8

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Caspase-4	B, E	protein	166	Homo sapiens	P49662 (AlphaFold model)
Caspase-4	C, D	protein	88	Homo sapiens	P49662 (AlphaFold model)
Gasdermin-D	A	protein	484	Homo sapiens	P57764 (AlphaFold model)

Sequence of entity 1 (B, E), FASTA

>23BB_1 Caspase-4 (chains B, E)
ALKLCPHEEFLRLCKERAEEIYPIKERNNRTRLALIICNTEFDHLPPRNGADFDITGMKE
LLEGLDYSVDVEENLTARDMESALRAFATRPEHKSSDSTFLVLMSHGILEGICGTVHDEK
KPDVLLYDTIFQIFNNRNCLSLKDKPKVIIVQAARGANRGELWVRD

Sequence of entity 2 (C, D), FASTA

>23BB_2 Caspase-4 (chains C, D)
AVYKTHVEKDFIAFCSSTPHNVSWRDSTMGSIFITQLITCFQKYSWCCHLEEVFRKVQQS
FETPRAKAQMPTIERLSMTRYFYLFPGN

Sequence of entity 3 (A), FASTA

>23BB_3 Gasdermin-D (chains A)
MGSAFERVVRRVVQELDHGGEFIPVTSLQSSTGFQPYCLVVRKPSSSWFWKPRYKCVNLS
IKDILEPDAAEPDVQRGRSFHFYDAMDGQIQGSVELAAPGQAKIAGGAAVSDSSSTSMNV
YSLSVDPNTWQTLLHERHLRQPEHKVLQQLRSRGDNVYVVTEVLQTQKEVEVTRTHKREG
SGRFSLPGATCLQGEGQGHLSQKKTVTIPSGSTLAFRVAQLVIDSDLDVLLFPDKKQRTF
QPPATGHKRSTSEGAWPQLPSGLSMMRCLHNFLTDGVPAEGAFTEDFQGLRAEVETISKE
LELLDRELCQLLLEGLEGVLRDQLALRALEEALEQGQSLGPVEPLDGPAGAVLECLVLSS
GMLVPELAIPVVYLLGALTMLSETQHKLLAEALESQTLLGPLELVGSLLEQSAPWQERST
MSLPPGLLGNSWGEGAPAWVLLDECGLELGEDTPHVCWEPQAQGRMCALYASLALLSGLS
QEPH

Primary citation

Cryo-EM structures of human caspase-4 in complex with full-length gasdermin D. Luan, Y., Chen, E.B., Mao, Y.D. Structure (2026).

Other PDB entries of the same protein (UniProt P49662 (AlphaFold model), which also has an AlphaFold model), best resolution first:

7WR6 1.96 Å, Crystal structure of ADP-riboxanated caspase-4 in complex with Af1521
7WR1 2.13 Å, P32 of caspase-4 C258A mutant in complex with OspC3 C-terminal ankyrin-repeat domain
6NRY 2.18 Å, Crystal structure of human caspase-4
7WR4 2.75 Å, Crystal structure of OspC3-calmodulin-caspase-4 complex
7WR0 2.8 Å, P32 of caspase-4 C258A mutant
7WR5 3.1 Å, Crystal structure of OspC3-calmodulin-caspase-4 complex binding with 2'-aF-NAD+
8J6K 3.12 Å, Crystal structure of pro-interleukin-18 and caspase-4 complex
8SPB 3.2 Å, Caspase-4/Pro-IL-18 complex
23BD 3.4 Å, Caspase-4 p22/p10 and human GSDMD complex
6KMZ 3.61 Å, caspase-4 P22/P10 C258A in complex with human GSDMD-C domain

Browse structure collections

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