Interaction of the IkappaBalpha C-terminal PEST sequence with NF-kappaB: insights into the inhibition of NF-kappaB DNA binding by IkappaBalpha.

ABSTRACT: The transcription factor NF-kappaB (p50/p65) binds either a kappaB DNA element or its inhibitor protein, IkappaBalpha, but these two binding events are mutually exclusive. The reason for this exclusivity is not obvious from the available crystal structure data. The C-terminal PEST-like sequence of IkappaBalpha appears to be involved in the process, but it is located in both of the published X-ray structures of the IkappaBalpha/NF-kappaB complex at a significant distance away from the DNA contact loop in the NF-kappaB DNA-binding domain. We have used nuclear magnetic resonance spectroscopy and differential isotopic labeling to probe the interactions between the p50/p65 NF-kappaB heterodimer and IkappaBalpha in solution. Our measurements are able to resolve a local structural discrepancy bet

SUBMITTER: Sue SC 

PROVIDER: S-EPMC2688455 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature