1L1M: Lactose operon repressor

Solution structure of a dimer of lac repressor DNA-binding domain complexed to its natural operator O1. Determined by solution NMR. Released 26 Jun 2002.

Method: Solution NMR
Organism: Escherichia coli
Chains: 4
Atoms: 1,891
Mol. weight: 27.76 kDa
Released: 26 Jun 2002

Explore 1L1M in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

1L1M contains 8 α-helices and 0 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: 4 helices, 0 β-strands

Element	Residues	Length
α-helix	6-13	8
α-helix	17-25	9
α-helix	32-44	13
α-helix	51-57	7

Chain B: 4 helices, 0 β-strands

Element	Residues	Length
α-helix	6-13	8
α-helix	17-24	8
α-helix	32-44	13
α-helix	51-57	7

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
5'-d(gpapaptptpgptpgpapgpcpgpgpaptpapapcpapaptptp*t)-3'	C	DNA	23
5'-d(apapaptptpgptptpaptpcpcpgpcptpcpapcpapaptptp*c)-3'	D	DNA	23
Lactose operon repressor	A, B	protein	62	Escherichia coli	P03023 (AlphaFold model)

Sequence of entity 1 (C), FASTA

>1L1M_1 5'-D(*GP*AP*AP*TP*TP*GP*TP*GP*AP*GP*CP*GP*GP*AP*TP*AP*AP*CP*AP*AP*TP*TP*T)-3' (chains C)
GAATTGTGAGCGGATAACAATTT

Sequence of entity 2 (D), FASTA

>1L1M_2 5'-D(*AP*AP*AP*TP*TP*GP*TP*TP*AP*TP*CP*CP*GP*CP*TP*CP*AP*CP*AP*AP*TP*TP*C)-3' (chains D)
AAATTGTTATCCGCTCACAATTC

Sequence of entity 3 (A, B), FASTA

>1L1M_3 Lactose operon repressor (chains A, B)
MKPVTLYDVAEYAGVSYQTVSRVVNQASHVSAKTREKVEAAMAELNYIPNRCAQQLAGKQ
SL

Primary citation

Plasticity in protein-DNA recognition: lac repressor interacts with its natural operator 01 through alternative conformations of its DNA-binding domain. Kalodimos, C.G., Bonvin, A.M., Salinas, R.K. et al. EMBO J (2002) 21:2866-2876. DOI 10.1093/emboj/cdf318 · PubMed

Other PDB entries of the same protein (UniProt P03023 (AlphaFold model), which also has an AlphaFold model), best resolution first:

8GOH 1.1 Å, Homotetramic Antiparallel Coiled-Coil of 23-residues LacI C-terminal tetramerization helix
1JYE 1.7 Å, Structure of a Dimeric Lac Repressor with C-terminal Deletion and K84L Substitution
2P9H 2.0 Å, High resolution structure of the Lactose Repressor bound to IPTG
3EDC 2.1 Å, Crystal Structure of a 1.6-hexanediol Bound Tetrameric Form of Escherichia coli…
1EFA 2.6 Å, Crystal structure of the lac repressor dimer bound to operator and the anti-inducer onpf
1TLF 2.6 Å, Unprecedented quaternary structure of E. Coli lac repressor core tetramer: implications…
1LBI 2.7 Å, Lac repressor
4RZS 2.71 Å, Lac repressor engineered to bind sucralose, unliganded tetramer
1JYF 3.0 Å, Structure of the Dimeric Lac Repressor with an 11-residue C-terminal Deletion.
4RZT 3.1 Å, Lac repressor engineered to bind sucralose, sucralose-bound tetramer
1LBH 3.2 Å, Intact lactose operon repressor with gratuitous inducer iptg
2PAF 3.5 Å, Crystal Structure of the Lactose Repressor bound to anti-inducer ONPF in induced state

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