9TF2: Echovirus 18, empty particle

Name: PDB 9TF2: Structure of echovirus 18, empty particle
Published: 2026-06-24
License: https://creativecommons.org/publicdomain/zero/1.0/
Keywords: virus

Structure of echovirus 18, empty particle. Determined by electron microscopy at 2.86 Å resolution. Released 24 Jun 2026.

Method: Electron microscopy
Resolution: 2.86 Å
Organism: Echovirus E18
Chains: 3
Atoms: 5,173
Mol. weight: 87.51 kDa
Released: 24 Jun 2026

Explore 9TF2 in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9TF2 contains 22 α-helices and 51 β-strands across 3 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, 14 β-strands

Element	Residues	Length	Sheet
α-helix	54-56	3
β-strand	57	1	1
α-helix	58-62	5
β-strand	66-71	6	2
α-helix	82-84	3
β-strand	86-89	4	3
α-helix	96-102	7
β-strand	105-119	15	2
β-strand	136-142	7	3
α-helix	155-158	4
β-strand	164-168	5	3
α-helix	172-174	3
β-strand	175-178	4	2
β-strand	187-188	2	2
β-strand	193	1	4
β-strand	194	1	5
β-strand	203	1	5
β-strand	213-218	6	3
β-strand	230-245	16	2
α-helix	247-249	3
α-helix	252-253	2
β-strand	270	1	6

Chain B: 7 helices, 21 β-strands

Element	Residues	Length	Sheet
β-strand	15-16	2	7
β-strand	23-24	2	7
β-strand	32-33	2	8
α-helix	34-36	3
β-strand	54-56	3	8
α-helix	58-60	3
β-strand	64-65	2	8
β-strand	69-71	3	9
β-strand	78-82	5	10
α-helix	84-86	3
α-helix	90-98	9
β-strand	102-111	10	8
β-strand	119-128	10	10
β-strand	134	1	11
α-helix	140-142	3
α-helix	143-145	3
β-strand	153-154	2	10
β-strand	156	1	12
β-strand	165	1	11
β-strand	168	1	12
α-helix	178-180	3
β-strand	186-190	5	10
β-strand	196-201	6	8
β-strand	210	1	8
β-strand	215	1	4
β-strand	218-229	12	10
β-strand	238-240	3	9
β-strand	241-252	12	8

Chain C: 7 helices, 16 β-strands

Element	Residues	Length	Sheet
β-strand	23	1	2
α-helix	31-33	3
β-strand	39-40	2	2
β-strand	42	1	1
α-helix	43-47	5
β-strand	51-53	3	13
β-strand	58	1	6
α-helix	65-67	3
β-strand	70-72	3	13
β-strand	84-87	4	14
α-helix	94-96	3
α-helix	100-105	6
β-strand	108	1	15
β-strand	111-121	11	13
β-strand	128-136	9	14
α-helix	141-143	3
α-helix	146-151	6
β-strand	153-158	6	14
β-strand	164-173	10	13
β-strand	190-200	11	14
β-strand	209-217	9	13
β-strand	222-223	2	13
β-strand	226	1	15

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Genome polyprotein	A	protein	287	Echovirus E18	Q8V635 (AlphaFold model)
Echovirus 18 viral protein 2	B	protein	260	Echovirus E18	Q8V635 (AlphaFold model)
Echovirus 18 viral protein 3	C	protein	239	Echovirus E18	Q8V635 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>9TF2_1 Genome polyprotein (chains A)
GDNQDRTVANTQPSGPSNSTEIPALTAVETGHTSQVDPSDTIQTRHVVNFHSRSESTIEN
FMGRAACVFMDQYKINGEETSTDRFAVWTINIREMAQLRRKCEMFTYMRFDIEMTMVITS
CQDQGTILDQDMPVLTHQIMYVPPGGPIPAKVDGYEWQTSTNPSVFWTEGNAPPRISIPF
ISVGNAYSSFYDGWSHFTQDGTYGYTTLNAMGKLYIRHVNRSSPHQITSTIRVYFKPKHI
KAWVPRPPRLCPYINKRDVNFVVTEITDSRTSITDTPHPEHSVLATH

Sequence of entity 2 (B), FASTA

>9TF2_2 Echovirus 18 viral protein 2 (chains B)
SPSAEECGYSDRVRSMTLGNSTITTQESANVVVGYGEWPSYLSDREATAEDQPTQPDVAT
CRFYTLESVQWEKTSPGWWWKFPEALKNMGLFGQNMHYHYLGRAGYTIHVQCNASKFHQG
CLLVVCVPEAEMGCADTDTTFPATELTTEDTPHVFTSDSITGKKVQAAVCNAGMGVGVGN
LTIFPHQWINLRTNNSATIVIPYINSVPMDNMFRHYNFTLMIIPFAPLNFTDGATAYVPI
TVTIAPMYAEYNGLRLASTQ

Sequence of entity 3 (C), FASTA

>9TF2_3 Echovirus 18 viral protein 3 (chains C)
GVPVLNTPGSNQFLTSDDYQSPSAMPQFDETPEMHIPGEVRNLMEIAEVDSVVPVNNVTG
KTKSMDAYQIPVGTGNTDKTKPIFSFQMDPGYSSVLKRTLLGEMLNYYAHWSGSVKLTFL
FCGSAMATGKLLISYSPPGASVPTSRKDAMLGTHIVWDIGLQSSCVLCVPWISQSHYRMV
QQDPYTSAGYITCWYQTNIVVPPGAPTSCDVLCFASACNDFSVRLLRDTPFMAQPGKLQ

Primary citation

Particles of echovirus 18 open to release their genomes in vivo. Mukhamedova, L., Buchta, D., Trebichalska, Z. et al. Proc Natl Acad Sci U S A (2026) 123:e2601182123-e2601182123. DOI 10.1073/pnas.2601182123 · PubMed

Other PDB entries of the same protein (UniProt Q8V635 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9TF0 2.26 Å, Structure of echovirus 18 in complex with neonatal Fc receptor
9TF1 2.44 Å, Structure of echovirus 18, activated particle
7B5F 2.9 Å, Structure of echovirus 18 in complex with neonatal Fc receptor
6HBG 3.16 Å, Echovirus 18 native particle
6HBJ 3.16 Å, Echovirus 18 empty particle
6HBH 3.36 Å, Echovirus 18 A-particle
6HBL 3.7 Å, Echovirus 18 Open particle without three pentamers
6HBK 3.8 Å, Echovirus 18 Open particle without one pentamer
6HHT 4.05 Å, Echovirus 18 Open particle without two pentamers
9S63 4.3 Å, Echovirus 18 in situ, virion, I4
9SPU 6.5 Å, Echovirus 18 particle missing one pentamer in situ, symmetrized reconstruction (C5)

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