9SRU: Mlc

Cryo-EM structure of Mlc in complex with ptsG operator DNA. Determined by electron microscopy at 2.47 Å resolution. Released 22 Jul 2026.

Method: Electron microscopy
Resolution: 2.47 Å
Organism: Escherichia coli
Chains: 8
Atoms: 14,466
Mol. weight: 235.51 kDa
Ligands: ZN
Released: 22 Jul 2026

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

Secondary structure: helices and β-sheets

9SRU contains 74 α-helices and 84 β-strands across 4 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: 17 helices, 21 β-strands

Element	Residues	Length	Sheet
α-helix	10-27	18
β-strand	31	1	1
α-helix	33-40	8
α-helix	44-56	13
β-strand	60-62	3	1
α-helix	74-75	2
β-strand	78-80	3	1
β-strand	86-93	8	2
β-strand	96-103	8	2
β-strand	108-115	8	2
α-helix	124-138	15
β-strand	146-152	7	2
β-strand	156-158	3	3
β-strand	163-166	4	3
β-strand	176	1	3
α-helix	180-186	7
β-strand	190-193	4	2
α-helix	195-206	12
β-strand	215-220	6	4
β-strand	224-230	7	4
β-strand	233-234	2	4
β-strand	243	1	4
α-helix	245-247	3
β-strand	249	1	5
β-strand	256	1	6
β-strand	262	1	6
β-strand	264	1	5
α-helix	266-269	4
α-helix	271-282	12
α-helix	297-305	9
α-helix	309-333	25
β-strand	337-341	5	4
α-helix	343-347	5
α-helix	348-362	15
α-helix	365-368	4
β-strand	372-375	4	4
α-helix	386-395	10
α-helix	398-403	6

Chains B and C: 19 helices, 21 β-strands

Element	Residues	Length	Sheet
α-helix	10-27	18
β-strand	31	1	7
α-helix	33-40	8
α-helix	44-56	13
β-strand	60-62	3	7
α-helix	74-75	2
β-strand	78-80	3	7
β-strand	86-93	8	8
β-strand	96-103	8	8
β-strand	108-115	8	8
α-helix	124-138	15
β-strand	146-153	8	8
β-strand	156-158	3	9
β-strand	163-166	4	9
β-strand	176	1	9
α-helix	181-186	6
β-strand	190-194	5	8
α-helix	195-206	12
β-strand	215-220	6	10
β-strand	224-230	7	10
β-strand	233-234	2	10
β-strand	243	1	10
α-helix	245-247	3
β-strand	249	1	11
α-helix	255	1
β-strand	256	1	12
α-helix	257	1
β-strand	262	1	12
β-strand	264	1	11
α-helix	266-269	4
α-helix	271-282	12
α-helix	297-306	10
α-helix	309-333	25
β-strand	337-341	5	10
α-helix	343-347	5
α-helix	348-362	15
α-helix	365-368	4
β-strand	372-375	4	10
α-helix	386-395	10
α-helix	398-403	6

Chain D: 19 helices, 21 β-strands

Element	Residues	Length	Sheet
α-helix	10-27	18
β-strand	31	1	19
α-helix	33-40	8
α-helix	44-56	13
β-strand	60-62	3	19
α-helix	74-75	2
β-strand	78-80	3	19
β-strand	86-93	8	20
β-strand	96-103	8	20
β-strand	108-115	8	20
α-helix	124-138	15
β-strand	146-152	7	20
β-strand	156-158	3	21
β-strand	163-166	4	21
β-strand	176	1	21
α-helix	180-186	7
β-strand	190-193	4	20
α-helix	195-206	12
β-strand	215-220	6	22
β-strand	224-230	7	22
β-strand	233-234	2	22
β-strand	243	1	22
α-helix	245-247	3
β-strand	249	1	23
α-helix	255	1
β-strand	256	1	24
α-helix	257	1
β-strand	262	1	24
β-strand	264	1	23
α-helix	266-269	4
α-helix	271-282	12
α-helix	297-305	9
α-helix	309-333	25
β-strand	337-341	5	22
α-helix	343-347	5
α-helix	348-362	15
α-helix	365-368	4
β-strand	372-375	4	22
α-helix	386-395	10
α-helix	398-403	6

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
DNA-binding transcriptional repressor Mlc	A, B, C, D	protein	455	Escherichia coli	P50456 (AlphaFold model)
DNA (27-mer)	E, H	DNA	29	Escherichia coli
DNA (27-mer)	F, G	DNA	29	Escherichia coli

Sequence of entity 1 (A, B, C, D), FASTA

>9SRU_1 DNA-binding transcriptional repressor Mlc (chains A, B, C, D)
MGGSHHHHHHGMASMTGGQQMGRDLYDDDDKDRWGSELEVLFQGPKLMVAENQPGHIDQI
KQTNAGAVYRLIDQLGPVSRIDLSRLAQLAPASITKIVREMLEAHLVQELEIKEAGNRGR
PAVGLVVETEAWHYLSLRISRGEIFLALRDLSSKLVVEESQELALKDDLPLLDRIISHID
QFFIRHQKKLERLTSIAITLPGIIDTENGIVHRMPFYEDVKEMPLGEALEQHTGVPVYIQ
HDISAWTMAEALFGASRGARDVIQVVIDHNVGAGVITDGHLLHAGSSSLVEIGHTQVDPY
GKRCYCGNHGCLETIASVDSILELAQLRLNQSMSSMLHGQPLTVDSLCQAALRGDLLAKD
IITGVGAHVGRILAIMVNLFNPQKILIGSPLSKAADILFPVISDSIRQQALPAYSQHISV
ESTQFSNQGTMAGAALVKDAMYNGSLLIRLLQGLE

Sequence of entity 2 (E, H), FASTA

>9SRU_2 DNA (27-MER) (chains E, H)
TTTATTTATTACACAGAGTAAAATAATTC

Sequence of entity 3 (F, G), FASTA

>9SRU_3 DNA (27-MER) (chains F, G)
GAATTATTTTACTCTGTGTAATAAATAAA

Ligands and cofactors

ID	Name	Formula	Copies
ZN	Zinc ion	Zn	4

Primary citation

Structural basis of Mlc-mediated transcriptional regulation of carbohydrate metabolism. Roth, P., Fender, I., Jeckelmann, J.M. et al. Nat Commun (2026) 17. DOI 10.1038/s41467-026-75270-8 · PubMed

Other PDB entries of the same protein (UniProt P50456 (AlphaFold model), which also has an AlphaFold model), best resolution first:

9SRW 2.3 Å, Cryo-EM structure of the Mlc tetramer in complex with the anti-repressor MtfA
1Z6R 2.7 Å, Crystal structure of Mlc from Escherichia coli
9SRT 2.74 Å, Cryo-EM structure of the Mlc tetramer
3BP8 2.85 Å, Crystal structure of Mlc/EIIB complex
9SRX 2.96 Å, Cryo-EM structure of the Mlc repressor in complex with the glucose-specific IICB…

Browse structure collections

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