1ooa
From Proteopedia
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CRYSTAL STRUCTURE OF NF-kB(p50)2 COMPLEXED TO A HIGH-AFFINITY RNA APTAMER
Overview
We have recently identified an RNA aptamer for the transcription factor, NF-kappaB p50 homodimer [(p50)2], which exhibits little sequence, resemblance to the consensus DNA target for (p50)2, but binds (p50)2 with, an affinity similar to that of the optimal DNA target. We describe here, the 2.45-A resolution x-ray crystal structure of the p50 RHR/RNA aptamer, complex. The structure reveals that two RNA molecules bind independent of, each other to the p50 N-terminal Ig-like domains. The RNA secondary, structure is comprised of a stem and a stem-loop separated by an internal, loop folded into a kinked helix because of the cross-strand stacking of, three internal loop guanines. These guanines, placed at the edge of the 3', helix, together with the major groove of the irregular 3' helix, form the, binding surface for p50. Each p50 monomer uses the same surface to, recognize the distorted RNA major groove as observed in the kappaB DNA/p50, RHR complex, resulting in strikingly similar interfaces. The structure, reveals how the aptamer specifically selects p50 and discriminates against, p65. We also discuss the physiological implications of RNA binding by, (p50)2.
About this Structure
1OOA is a Single protein structure of sequence from Mus musculus. Full crystallographic information is available from OCA.
Reference
Crystal structure of NF-kappaB (p50)2 complexed to a high-affinity RNA aptamer., Huang DB, Vu D, Cassiday LA, Zimmerman JM, Maher LJ 3rd, Ghosh G, Proc Natl Acad Sci U S A. 2003 Aug 5;100(16):9268-73. Epub 2003 Jul 28. PMID:12886018
Page seeded by OCA on Tue Nov 20 23:03:41 2007
