Publication Date:
2012-04-15
Description:
Rap1 is an essential DNA-binding factor from the yeast Saccharomyces cerevisiae involved in transcription and telomere maintenance. Its binding to DNA targets Rap1 at particular loci , and may optimize its ability to form functional macromolecular assemblies. It is a modular protein, rich in large potentially unfolded regions, and comprising BRCT, Myb and RCT well-structured domains. Here, we present the architectures of Rap1 and a Rap1/DNA complex, built through a step-by-step integration of small angle X-ray scattering, X-ray crystallography and nuclear magnetic resonance data. Our results reveal Rap1 structural adjustment upon DNA binding that involves a specific orientation of the C-terminal (RCT) domain with regard to the DNA binding domain (DBD). Crystal structure of DBD in complex with a long DNA identifies an essential wrapping loop, which constrains the orientation of the RCT and affects Rap1 affinity to DNA. Based on our structural information, we propose a model for Rap1 assembly at telomere.
Print ISSN:
0305-1048
Electronic ISSN:
1362-4962
Topics:
Biology
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