PDBsum entry 5ckf

Hydrolase

PDB id: 5ckf

Contents

Protein chains

103 a.a.

Metals

_NA

Waters ×9

PDB id:

5ckf

Name:

Hydrolase

Title:

E. Coli mazf e24a form i

Structure:

Endoribonuclease mazf. Chain: a, b. Synonym: toxin mazf,mRNA interferase mazf. Engineered: yes. Mutation: yes

Source:

Escherichia coli (strain k12). Organism_taxid: 83333. Gene: mazf, chpa, chpak, b2782, jw2753. Expressed in: escherichia coli. Expression_system_taxid: 562

Resolution:

2.80Å R-factor: 0.239 R-free: 0.300

Authors:

V.Zorzini,R.Loris

Key ref:

V.Zorzini et al. (2016). Substrate Recognition and Activity Regulation of the Escherichia coli mRNA Endonuclease MazF. J Biol Chem, 291, 10950-10960. PubMed id: 27026704 DOI: 10.1074/jbc.M116.715912

Date:

15-Jul-15 Release date: 06-Apr-16

Protein chains

P0AE70  (MAZF_ECOLI) -  Endoribonuclease toxin MazF from Escherichia coli (strain K12)

Seq: 111 a.a.

Struc: 103 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.27.- - ?????

DOI no: 10.1074/jbc.M116.715912

J Biol Chem 291:10950-10960 (2016)

PubMed id: 27026704

Substrate Recognition and Activity Regulation of the Escherichia coli mRNA Endonuclease MazF.

V.Zorzini, A.Mernik, J.Lah, Y.G.Sterckx, N.De Jonge, A.Garcia-Pino, H.De Greve, W.Versées, R.Loris.

ABSTRACT

Escherichia coli MazF (EcMazF) is the archetype of a large family of ribonucleases involved in bacterial stress response. The crystal structure of EcMazF in complex with a 7-nucleotide substrate mimic explains the relaxed substrate specificity of the E. coli enzyme relative to its Bacillus subtilis counterpart and provides a framework for rationalizing specificity in this enzyme family. In contrast to a conserved mode of substrate recognition and a conserved active site, regulation of enzymatic activity by the antitoxin EcMazE diverges from its B. subtilis homolog. Central in this regulation is an EcMazE-induced double conformational change as follows: a rearrangement of a crucial active site loop and a relative rotation of the two monomers in the EcMazF dimer. Both are induced by the C-terminal residues Asp-78-Trp-82 of EcMazE, which are also responsible for strong negative cooperativity in EcMazE-EcMazF binding. This situation shows unexpected parallels to the regulation of the F-plasmid CcdB activity by CcdA and further supports a common ancestor despite the different activities of the MazF and CcdB toxins. In addition, we pinpoint the origin of the lack of activity of the E24A point mutant of EcMazF in its inability to support the substrate binding-competent conformation of EcMazF.