3IAX: TolB box of Colicin A

The crystal structure of the TolB box of Colicin A in complex with TolB reveals important differences in the recruitment of the common TolB translocation portal used by group A colicins. Determined by X-ray diffraction at 2.6 Å resolution. Released 13 Oct 2009.

Method: X-ray diffraction
Resolution: 2.6 Å
Organisms: Escherichia coli, Citrobacter freundii
Chains: 2
Atoms: 3,175
Mol. weight: 59.19 kDa
Ligands: CA
Released: 13 Oct 2009

Explore 3IAX in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

3IAX contains 10 α-helices and 31 β-strands across 1 chain. 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, 31 β-strands

Element	Residues	Length	Sheet
α-helix	34	1
β-strand	35-37	3	1
β-strand	38-39	2	2
α-helix	40-42	3
β-strand	43-44	2	2
α-helix	54-64	11
β-strand	68-70	3	1
α-helix	71-72	2
α-helix	73-75	3
α-helix	88-92	5
β-strand	98-106	9	2
β-strand	111-120	10	2
β-strand	128-137	10	2
α-helix	138-140	3
α-helix	141-157	17
β-strand	166-172	7	3
β-strand	180-186	7	3
β-strand	193-198	6	3
β-strand	202-207	6	4
β-strand	213-218	6	4
β-strand	225-230	6	4
β-strand	236-240	5	4
β-strand	246-251	6	5
β-strand	257-262	6	5
β-strand	269-274	6	5
β-strand	280-282	3	5
β-strand	290-295	6	6
β-strand	301-306	6	6
β-strand	313-318	6	6
β-strand	325-326	2	6
β-strand	333-339	7	7
β-strand	345-352	8	7
β-strand	355-362	8	7
β-strand	368-370	3	7
β-strand	378-382	5	8
β-strand	388-395	8	8
β-strand	398-405	8	8
β-strand	411-413	3	8
α-helix	414-416	3
β-strand	420-426	7	3
α-helix	427-429	3

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Protein tolB	A	protein	438	Escherichia coli	P0A855 (AlphaFold model)
Colicin-A	B	protein	115	Citrobacter freundii	P04480 (AlphaFold model)

Sequence of entity 1 (A), FASTA

>3IAX_1 Protein tolB (chains A)
MKQALRVAFGFLILWASVLHAEVRIVIDSGVDSGRPIGVVPFQWAGPGAAPEDIGGIVAA
DLRNSGKFNPLDRARLPQQPGSAQEVQPAAWSALGIDAVVVGQVTPNPDGSYNVAYQLVD
TGGAPGTVLAQNSYKVNKQWLRYAGHTASDEVFEKLTGIKGAFRTRIAYVVQTNGGQFPY
ELRVSDYDGYNQFVVHRSPQPLMSPAWSPDGSKLAYVTFESGRSALVIQTLANGAVRQVA
SFPRHNGAPAFSPDGSKLAFALSKTGSLNLYVMDLASGQIRQVTDGRSNNTEPTWFPDSQ
NLAFTSDQAGRPQVYKVNINGGAPQRITWEGSQNQDADVSSDGKFMVMVSSNGGQQHIAK
QDLATGGVQVLSSTFLDETPSLAPNGTMVIYSSSQGMGSVLNLVSTDGRFKARLPATDGQ
VKFPAWSPYLLEHHHHHH

Sequence of entity 2 (B), FASTA

>3IAX_2 Colicin-A (chains B)
MPGFNYGGKGDGTGWSSERGSGPEPGGGSHGNSGGHDRGDSSNVGNESVTVMKPGDSYNT
PWGKVIINAAGQPTMNGTVMTADNSSMVPYGRGFTRVLNSLVNNPVSLEHHHHHH

Ligands and cofactors

ID	Name	Formula	Copies
CA	Calcium ion	Ca	1

Water and common crystallization additives (NA, GOL) are not listed.

Primary citation

The crystal structure of the TolB box of colicin A in complex with TolB reveals important differences in the recruitment of the common TolB translocation portal used by group A colicins. Zhang, Y., Li, C., Vankemmelbeke, M.N. et al. Mol Microbiol (2009) 75:623-636. DOI 10.1111/j.1365-2958.2009.06808.x · PubMed

Other PDB entries of the same protein (UniProt P0A855 (AlphaFold model), which also has an AlphaFold model), best resolution first:

2HQS 1.5 Å, Crystal structure of TolB/Pal complex
2W8B 1.86 Å, Crystal structure of processed TolB in complex with Pal
1CRZ 1.95 Å, Crystal structure of the E. Coli tolb protein
1C5K 2.0 Å, The structure of tolb, an essential component of the tol-dependent translocation system…
2IVZ 2.0 Å, Structure of TolB in complex with a peptide of the colicin E9 T- domain
4JML 2.0 Å, Crystal structure of the TolB(P201C)-ColicinE9 TBE peptide(A33C) complex.
7NST 3.7 Å, ColicinE9 partial translocation complex
7NSU 4.7 Å, ColicinE9 intact translocation complex
9A2L Model of E. coli TolB by in-cell photo-crosslinking MS and deep learning

Browse structure collections

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