1IHF: Integration host factor/dna complex

Integration host factor/dna complex. Determined by X-ray diffraction at 2.5 Å resolution. Released 12 Feb 1997.

Method: X-ray diffraction
Resolution: 2.5 Å
Organism: Escherichia coli
Chains: 5
Atoms: 3,337
Mol. weight: 45.22 kDa
Ligands: CD
Released: 12 Feb 1997

Explore 1IHF in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1IHF contains 7 α-helices and 12 β-strands across 2 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: 3 helices, 6 β-strands

Element	Residues	Length	Sheet
β-strand	3	1	1
α-helix	5-16	12
α-helix	20-39	20
β-strand	44-46	3	2
β-strand	50-57	8	2
β-strand	60-63	4	3
β-strand	70-73	4	3
β-strand	76-83	8	2
α-helix	85-92	8

Chain B: 4 helices, 6 β-strands

Element	Residues	Length	Sheet
β-strand	2	1	2
α-helix	3-13	11
α-helix	19-38	20
β-strand	43-45	3	1
β-strand	49-56	8	1
β-strand	59-62	4	4
β-strand	69-72	4	4
α-helix	73-74	2
β-strand	75-82	8	1
α-helix	84-90	7

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
DNA (35-mer)	C	DNA	35
DNA (5'-d(gpgpcpcpapapapapapapgpcpaptp*t)-3')	D	DNA	15
DNA (5'-d(gpcptptpaptpcpapaptptptpgptptpgpc papcpc)-3')	E	DNA	20
Protein (integration host factor (ALPHA) (ihf))	A	protein	99	Escherichia coli	P0A6X7 (AlphaFold model)
Protein (integration host factor (BETA) (ihf))	B	protein	94	Escherichia coli	P0A6Y1 (AlphaFold model)

Sequence of entity 1 (C), FASTA

>1IHF_1 DNA (35-MER) (chains C)
CGGTGCAACAAATTGATAAGCAATGCTTTTTTGGC

Sequence of entity 2 (D), FASTA

>1IHF_2 DNA (5'-D(*GP*GP*CP*CP*AP*AP*AP*AP*AP*AP*GP*CP*AP*TP*T)-3') (chains D)
GGCCAAAAAAGCATT

Sequence of entity 3 (E), FASTA

>1IHF_3 DNA (5'-D(*GP*CP*TP*TP*AP*TP*CP*AP*AP*TP*TP*TP*GP*TP*TP*GP*C P*AP*CP*C)-3') (chains E)
GCTTATCAATTTGTTGCACC

Sequence of entity 4 (A), FASTA

>1IHF_4 PROTEIN (INTEGRATION HOST FACTOR (ALPHA) (IHF)) (chains A)
MALTKAEMSEYLFDKLGLSKRDAKELVELFFEEIRRALENGEQVKLSGFGNFDLRDKNQR
PGRNPKTGEDIPITARRVVTFRPGQKLKSRVENASPKDE

Sequence of entity 5 (B), FASTA

>1IHF_5 PROTEIN (INTEGRATION HOST FACTOR (BETA) (IHF)) (chains B)
MTKSELIERLATQQSHIPAKTVEDAVKEMLEHMASTLAQGERIEIRGFGSFSLHYRAPRT
GRNPKTGDKVELEGKYVPHFKPGKELRDRANIYG

Ligands and cofactors

ID	Name	Formula	Copies
CD	Cadmium ion	Cd	15

Primary citation

Crystal structure of an IHF-DNA complex: a protein-induced DNA U-turn. Rice, P.A., Yang, S., Mizuuchi, K. et al. Cell (1996) 87:1295-1306. DOI 10.1016/S0092-8674(00)81824-3 · PubMed

Other PDB entries of the same protein (UniProt P0A6X7 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1OWF 1.95 Å, Crystal structure of a mutant IHF (BetaE44A) complexed with the native H' Site
2HT0 2.0 Å, IHF bound to doubly nicked DNA
1OWG 2.1 Å, Crystal structure of WT IHF complexed with an altered H' site (T44A)
1OUZ 2.41 Å, Crystal structure of a mutant IHF (BetaE44A) complexed with a variant H' Site (T44A)
2IIE 2.41 Å, single chain Integration Host Factor protein (scIHF2) in complex with DNA
2IIF 2.72 Å, single chain Integration Host Factor mutant protein (scIHF2-K45aE) in complex with DNA
9F10 2.94 Å, CryoEM structure of the F plasmid relaxosome with TraI in its TE mode, without accessory…
9F0Z 3.42 Å, CryoEM structure of the F plasmid relaxosome with truncated TraI1-863 in its TE mode,…
9F12 3.42 Å, CryoEM structure of the F plasmid relaxosome with oriT DNA ss-27_-3ds-2_+143 and TraI…
9F0Y 3.45 Å, CryoEM structure of the F plasmid relaxosome with TraI in its TE mode, derived from the…
5WFE 3.64 Å, Cas1-Cas2-IHF-DNA holo-complex
9F11 3.68 Å, CryoEM structure of the F plasmid relaxosome with oriT DNA ss-27_+3ds+4_+143 and TraI…

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