Immunity proteins: enzyme inhibitors that avoid the active site

Kleanthous, C. and Walker, D. (2001) Immunity proteins: enzyme inhibitors that avoid the active site. Trends in Biochemical Sciences, 26(10), pp. 624-631. (doi: 10.1016/S0968-0004(01)01941-7) (PMID:11590016)

Full text not currently available from Enlighten.


Immunity proteins are high affinity inhibitors of colicins – SOS-induced toxins released by bacteria during times of stress. Recent work has shown that nuclease-specific immunity proteins are exosite inhibitors, binding adjacent to the enzyme active site and inhibiting colicin activity indirectly. Unusually, their binding sites comprise a near contiguous sequence that lies N-terminal to active site sequences, raising the possibility that immunity proteins bind colicins co-translationally. Exosite binding accounts for the extensive sequence diversity seen at the interfaces of colicin–immunity protein complexes, which is not only a selective advantage to colicin-producing bacteria, but also represents a powerful model system for studying specificity in protein–protein recognition.

Item Type:Articles
Glasgow Author(s) Enlighten ID:Walker, Professor Daniel
Authors: Kleanthous, C., and Walker, D.
College/School:College of Medical Veterinary and Life Sciences > School of Infection & Immunity
Journal Name:Trends in Biochemical Sciences
Publisher:Elsevier (Cell Press)
ISSN (Online):1362-4326

University Staff: Request a correction | Enlighten Editors: Update this record