9QUQ: TolQR conformation2 in SMA nanodiscs

cryo-EM structure of TolQR conformation2 in SMA nanodiscs. Determined by electron microscopy at 3.28 Å resolution. Released 17 Dec 2025.

Method: Electron microscopy
Resolution: 3.28 Å
Organism: Escherichia coli str. K-12 substr. MG1655
Chains: 8
Atoms: 9,178
Mol. weight: 202.15 kDa
Released: 17 Dec 2025

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

Secondary structure: helices and β-sheets

9QUQ contains 45 α-helices and 0 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: 10 helices, 0 β-strands

Element	Residues	Length
α-helix	6-12	7
α-helix	15-56	42
α-helix	62-69	8
α-helix	70-75	6
α-helix	79-94	16
α-helix	101-123	23
α-helix	127-158	32
α-helix	164-167	4
α-helix	168-171	4
α-helix	172-219	48

Chain B: 8 helices, 0 β-strands

Element	Residues	Length
α-helix	6-12	7
α-helix	15-56	42
α-helix	62-69	8
α-helix	70-72	3
α-helix	79-96	18
α-helix	101-123	23
α-helix	128-157	30
α-helix	164-221	58

Chain C: 8 helices, 0 β-strands

Element	Residues	Length
α-helix	6-12	7
α-helix	15-56	42
α-helix	62-69	8
α-helix	70-72	3
α-helix	79-96	18
α-helix	101-123	23
α-helix	127-158	32
α-helix	168-221	54

Chain D: 8 helices, 0 β-strands

Element	Residues	Length
α-helix	6-12	7
α-helix	15-56	42
α-helix	62-71	10
α-helix	73-75	3
α-helix	79-96	18
α-helix	103-123	21
α-helix	128-156	29
α-helix	164-221	58

Chain E: 8 helices, 0 β-strands

Element	Residues	Length
α-helix	6-12	7
α-helix	15-56	42
α-helix	62-71	10
α-helix	73-75	3
α-helix	79-94	16
α-helix	101-123	23
α-helix	128-158	31
α-helix	164-219	56

Chain F: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	21-32	12

Chain G: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	19-34	16

Chain H: 1 helix, 0 β-strands

Element	Residues	Length	Sheet
α-helix	8-33	26

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Tol-Pal system protein TolA	H	protein	421	Escherichia coli str. K-12 substr. MG1655	P19934 (AlphaFold model)
Tol-Pal system protein TolQ	A, B, C, D, E	protein	230	Escherichia coli str. K-12 substr. MG1655	P0ABU9 (AlphaFold model)
Tol-Pal system protein TolR	F, G	protein	142	Escherichia coli str. K-12 substr. MG1655	P0ABV6 (AlphaFold model)

Sequence of entity 1 (H), FASTA

>9QUQ_1 Tol-Pal system protein TolA (chains H)
MSKATEQNDKLKRAIIISAVLHVILFAALIWSSFDENIEASAGGGGGSSIDAVMVDSGAV
VEQYKRMQSQESSAKRSDEQRKMKEQQAAEELREKQAAEQERLKQLEKERLAAQEQKKQA
EEAAKQAELKQKQAEEAAAKAAADAKAKAEADAKAAEEAAKKAAADAKKKAEAEAAKAAA
EAQKKAEAAAAALKKKAEAAEAAAAEARKKAATEAAEKAKAEAEKKAAAEKAAADKKAAA
EKAAADKKAAEKAAAEKAAADKKAAAEKAAADKKAAAAKAAAEKAAAAKAAAEADDIFGE
LSSGKNAPKTGGGAKGNNASPAGSGNTKNNGASGADINNYAGQIKSAIESKFYDASSYAG
KTCTLRIKLAPDGMLLDIKPEGGDPALCQAALAAAKLAKIPKPPSQAVYEVFKNAPLDFK
P

Sequence of entity 2 (A, B, C, D, E), FASTA

>9QUQ_2 Tol-Pal system protein TolQ (chains A, B, C, D, E)
MTDMNILDLFLKASLLVKLIMLILIGFSIASWAIIIQRTRILNAAAREAEAFEDKFWSGI
ELSRLYQESQGKRDNLTGSEQIFYSGFKEFVRLHRANSHAPEAVVEGASRAMRISMNREL
ENLETHIPFLGTVGSISPYIGLFGTVWGIMHAFIALGAVKQATLQMVAPGIAEALIATAI
GLFAAIPAVMAYNRLNQRVNKLELNYDNFMEEFTAILHRQAFTVSESNKG

Sequence of entity 3 (F, G), FASTA

>9QUQ_3 Tol-Pal system protein TolR (chains F, G)
MARARGRGRRDLKSEINIVPLLDVLLVLLLIFMATAPIITQSVEVDLPDATESQAVSSND
NPPVIVEVSGIGQYTVVVEKDRLERLPPEQVVAEVSSRFKANPKTVFLIGGAKDVPYDEI
IKALNLLHSAGVKSVGLMTQPI

Primary citation

Deciphering the molecular mechanism of the bacterial division motor TolQRA. Shen, C., Xie, T., Luo, Y. et al. Cell Discov (2025) 11:87-87. DOI 10.1038/s41421-025-00841-w · PubMed

Other PDB entries of the same protein (UniProt P19934 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1TOL 1.85 Å, Fusion of N-terminal domain of the minor coat protein from gene III in phage M13, and…
3QDP 2.15 Å, Structural characterization of the interaction of colicin A, colicin N, and TolB with…
3QDR 2.65 Å, Structural characterization of the interaction of colicin A, colicin N, and TolB with…
9DDM 2.94 Å, E. coli TolAQR conformation I
9DDN 3.18 Å, E. coli TolAQR conformation II
9KPZ 3.18 Å, Structure of TolQRA complex at pH 5.4 from E.coli
9QVD 3.52 Å, cryo-EM structure of TolQRA in nanodiscs
9K49 3.6 Å, Cryo-EM structure of inner membrane TolQRA complex in CYMAL-6-Neopentyl Glycol detergent…
9KQ0 3.6 Å, Structure of TolQRA complex at pH 8.0 from E.coli
9KCH 4.19 Å, Cryo-EM structure of inner membrane TolQRA complex in CYMAL-6-Neopentyl Glycol detergent…
1S62 Solution structure of the Escherichia coli TolA C-terminal domain

Browse structure collections

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