1gji
From Proteopedia
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Crystal structure of c-Rel bound to DNA
Overview
BACKGROUND: The proto-oncogene product c-Rel is a Rel/NF-kappaB family, transcription factor that plays a critical role in lymphoid cell, development and mediates CD28-induced expression of interleukin 2 (IL-2)., The CD28 response element (CD28RE) in the IL-2 enhancer is nonameric and, similar to the kappaB DNA target sites recognized by p65 homodimers., RESULTS: We have determined and refined the X-ray crystal structure of the, c-Rel homodimer complexed to the CD28RE DNA site, 5'-AGAAATTCC-3', to 2.85, A resolution. The c-Rel homodimer binds CD28RE in a mode similar to that, observed in the p65/IL-8 kappaB crystallographic complex. Binding studies, reveal that the c-Rel homodimer recognizes the CD28RE with higher affinity, as compared to other canonical kappaB sequences despite the nonconsensus, A:T base pair at the 5' end of the CD28RE. Preferential recognition of the, CD28RE by c-Rel results from the direct contacts between the protein and, the DNA as well as intrasubunit interactions between the beta(f)-beta(g), loop in the dimerization domain and the DNA-contacting loop L1 of the, N-terminal domain. Not only do these loops have different conformations in, other Rel/DNA crystallographic complexes, but they also contain two of the, five oncogenic point mutations found in v-Rel. CONCLUSIONS: The current, structure indicates that a non-DNA-contacting loop in the dimerization, domain and the DNA-contacting loop L1 may play critical roles in defining, affinity and specificity. Two amino acid changes in these segments may, account for the differential DNA binding by v-Rel as compared to that of, c-Rel.
About this Structure
1GJI is a Single protein structure of sequence from Gallus gallus. Full crystallographic information is available from OCA.
Reference
X-ray crystal structure of proto-oncogene product c-Rel bound to the CD28 response element of IL-2., Huang DB, Chen YQ, Ruetsche M, Phelps CB, Ghosh G, Structure. 2001 Aug;9(8):669-78. PMID:11587641
Page seeded by OCA on Tue Nov 20 16:06:44 2007
