PDBsum entry 4beb

Hydrolase

PDB id: 4beb

Contents

Protein chains

839 a.a.

Ligands

ATP ×4

Metals

_MG ×4

PDB id:

4beb

Name:

Hydrolase

Title:

Mutant (k220e) of the hsdr subunit of the ecor124i restriction enzyme in complex with atp

Structure:

Type i restriction enzyme hsdr. Chain: a, b, c, d. Engineered: yes. Mutation: yes

Source:

Escherichia coli. Organism_taxid: 562. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.99Å R-factor: 0.256 R-free: 0.297

Authors:

E.Csefalvay,M.Lapkouski,A.Guzanova,L.Csefalvay,T.Baikova,I.Shevelev, P.Janscak,I.K.Smatanova,S.Panjikar,J.Carey,M.Weiserova,R.Ettrich

Key ref:

E.Csefalvay et al. (2015). Functional coupling of duplex translocation to DNA cleavage in a type I restriction enzyme. Plos One, 10, e0128700. PubMed id: 26039067 DOI: 10.1371/journal.pone.0128700

Date:

07-Mar-13 Release date: 26-Mar-14

Supersedes:

2y3t

Protein chains

P10486  (T1R1_ECOLX) -  Type I restriction enzyme EcoR124I/EcoR124II endonuclease subunit from Escherichia coli

Seq: 1038 a.a.

Struc: 839 a.a.*

* PDB and UniProt seqs differ at 1 residue position (black cross)

Enzyme reactions

• Enzyme class: E.C.3.1.21.3 - type I site-specific deoxyribonuclease.
• Reaction: Endonucleolytic cleavage of DNA to give random double-stranded fragments with terminal 5'-phosphate; ATP is simultaneously hydrolyzed.

DOI no: 10.1371/journal.pone.0128700

Plos One 10:e0128700 (2015)

PubMed id: 26039067

Functional coupling of duplex translocation to DNA cleavage in a type I restriction enzyme.

E.Csefalvay, M.Lapkouski, A.Guzanova, L.Csefalvay, T.Baikova, I.Shevelev, V.Bialevich, K.Shamayeva, P.Janscak, I.Kuta Smatanova, S.Panjikar, J.Carey, M.Weiserova, R.Ettrich.

ABSTRACT

Type I restriction-modification enzymes are multifunctional heteromeric complexes with DNA cleavage and ATP-dependent DNA translocation activities located on motor subunit HsdR. Functional coupling of DNA cleavage and translocation is a hallmark of the Type I restriction systems that is consistent with their proposed role in horizontal gene transfer. DNA cleavage occurs at nonspecific sites distant from the cognate recognition sequence, apparently triggered by stalled translocation. The X-ray crystal structure of the complete HsdR subunit from E. coli plasmid R124 suggested that the triggering mechanism involves interdomain contacts mediated by ATP. In the present work, in vivo and in vitro activity assays and crystal structures of three mutants of EcoR124I HsdR designed to probe this mechanism are reported. The results indicate that interdomain engagement via ATP is indeed responsible for signal transmission between the endonuclease and helicase domains of the motor subunit. A previously identified sequence motif that is shared by the RecB nucleases and some Type I endonucleases is implicated in signaling.