1GVN

Crystal Structure of the Plasmid Maintenance System Epsilon /Zeta : Functional Mechanism of Toxin Zeta and Inactivation by Epsilon 2 Zeta 2 Complex Formation

(2003) Proc Natl Acad Sci U S A 100: 1661

• PubMed: 12571357 Search on PubMedSearch on PubMed Central
• DOI: https://doi.org/10.1073/pnas.0434325100
• Primary Citation of Related Structures:  
  1GVN


• PubMed Abstract: 
  

  Programmed cell death in prokaryotes is frequently found as postsegregational killing. It relies on antitoxin/toxin systems that secure stable inheritance of low and medium copy number plasmids during cell division and kill cells that have lost the plasmid. The broad-host-range, low-copy-number plasmid pSM19035 from Streptococcus pyogenes carries the genes encoding the antitoxin/toxin system epsilon/zeta and antibiotic resistance proteins, among others. The crystal structure of the biologically nontoxic epsilon(2)zeta(2) protein complex at a 1.95-A resolution and site-directed mutagenesis showed that free zeta acts as phosphotransferase by using ATPGTP. In epsilon(2)zeta(2), the toxin zeta is inactivated because the N-terminal helix of the antitoxin epsilon blocks the ATPGTP-binding site. To our knowledge, this is the first prokaryotic postsegregational killing system that has been entirely structurally characterized.

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Organizational Affiliation: 

Institut für Kristallographie, Freie Universität Berlin, Takustrasse 6, D-14195 Berlin, Germany.