A disulfide driven domain swap switches off the activity of Shigella IpaH9.8 E3 ligase
Seyedarabi, A., Sullivan, J.A., Sasakawa, C., Pickersgill, R.W.(2010) FEBS Lett 584: 4163-4168
- PubMed: 20831869 
- DOI: https://doi.org/10.1016/j.febslet.2010.09.006
- Primary Citation of Related Structures:  
3L3P - PubMed Abstract: 
We show that the monomeric form of Shigella IpaH9.8 E3 ligase catalyses the ubiquitination of human U2AF35 in vitro, providing a molecular mechanism for the observed in vivo effect. We further discover that under non-reducing conditions IpaH9.8 undergoes a domain swap driven by the formation of a disulfide bridge involving the catalytic cysteine and that this dimer is unable to catalyse the ubiquitination of U2AF35. The crystal structure of the domain-swapped dimer is presented. The redox inactivation of IpaH9.8 could be a mechanism of regulating the activity of the IpaH9.8 E3 ligase in response to cell damage so that the host cell in which the bacteria resides is maintained in a benign state suitable for bacterial survival.
Organizational Affiliation: 
School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom. a.seyedarabi@qmul.ac.uk