Database accession: MF2120019
Name: Escherichia coli met repressor (MetJ)
PDB ID: 1cmb
Experimental method: X-ray (1.80 Å)
Assembly: homodimer
Source organism: Escherichia coli
Primer publication of the structure:
Rafferty JB, Somers WS, Saint-Girons I, Phillips SE
Three-dimensional crystal structures of Escherichia coli met repressor with and without corepressor.
(1989) Nature 341: 705-10
PMID: 2677753
Abstract:
The three-dimensional crystal structure of met repressor, in the presence or absence of bound corepressor (S-adenosylmethionine), shows a dimer of intertwined monomers, which do not have the helix-turn-helix motif characteristic of other bacterial repressor and activator structures. We propose that the interaction of met repressor with DNA occurs through either a pair of symmetry-related alpha-helices or a pair of beta-strands, and suggest a model for binding of several dimers to met operator regions.
Molecular function:
transcription factor activity, sequence-specific DNA binding Interacting selectively and non-covalently with a specific DNA sequence in order to modulate transcription. The transcription factor may or may not also interact selectively with a protein or macromolecular complex.
Biological process:
methionine biosynthetic process The chemical reactions and pathways resulting in the formation of methionine (2-amino-4-(methylthio)butanoic acid), a sulfur-containing, essential amino acid found in peptide linkage in proteins.
transcription, DNA-templated The cellular synthesis of RNA on a template of DNA.
negative regulation of transcription, DNA-templated Any process that stops, prevents, or reduces the frequency, rate or extent of cellular DNA-templated transcription.
Cellular component:
Entry contents: 2 distinct polypeptide molecules
Chains: A, B
Notes: No modifications of the original PDB file. Chain identifiers are identical with the PDB's identifiers.
Number of unique protein segments: 1
Name: Met repressor
Source organism: Escherichia coli
Length: 104 residues
Sequence:Sequence according to PDB SEQRESAEWSGEYISPYAEHGKKSEQVKKITVSIPLKVLKILTDERTRRQVNNLRHATNSELLCEAFLHAFTGQPLPDDADLRKERSDEIPEAAKEIMREMGINPETWEY
UniProtKB AC: P0A8U6 (positions: 2-105)
Coverage: 99%UniRef90 AC: UniRef90_A7ZUF7 (positions: 2-105)
Name: Met repressor
Source organism: Escherichia coli
Length: 104 residues
Sequence:Sequence according to PDB SEQRESAEWSGEYISPYAEHGKKSEQVKKITVSIPLKVLKILTDERTRRQVNNLRHATNSELLCEAFLHAFTGQPLPDDADLRKERSDEIPEAAKEIMREMGINPETWEY
UniProtKB AC: P0A8U6 (positions: 2-105)
Coverage: 99%UniRef90 AC: UniRef90_A7ZUF7 (positions: 2-105)
Complex evidence:
MetJ was shown by differential scanning calorimetry to follow a two-state folding and dimerization (PMID: 1390748).