Ghosh Gourisankar, Huang De-Bin, Huxford Tom
Department of Chemistry & Biochemistry, University of California San Diego, Mail Code 0359, Urey Hall 5230, 9500 Gilman Drive, La Jolla, CA 92093-0359, USA.
Curr Opin Struct Biol. 2004 Feb;14(1):21-7. doi: 10.1016/j.sbi.2004.01.004.
During the past two decades, structural and biophysical studies of DNA-protein and RNA-protein complexes have enhanced our understanding of the physico-chemical basis of nucleic acid recognition by proteins. However, it remains unclear what protein surface features are most important for nucleic acid binding and whether the same protein surface could bind specifically to both DNA and RNA. The recently described X-ray crystal structure of the transcription factor NF-kappaB p50 homodimer bound to a high-affinity RNA aptamer allows the direct comparison of NF-kappaB-RNA and NF-kappaB-DNA binding modes. The RNA aptamer, which bears no sequence homology to natural NF-kappaB DNA targets, adopts a structure with similar physico-chemical properties to kappaB DNA and contacts a common nucleic-acid-binding 'consensus surface' on the p50 homodimer.
在过去二十年中，对DNA-蛋白质和RNA-蛋白质复合物的结构及生物物理研究增进了我们对蛋白质识别核酸的物理化学基础的理解。然而，目前仍不清楚蛋白质的哪些表面特征对核酸结合最为重要，以及同一蛋白质表面是否能特异性结合DNA和RNA。最近报道的转录因子NF-κB p50同型二聚体与高亲和力RNA适体结合的X射线晶体结构，使得直接比较NF-κB-RNA和NF-κB-DNA的结合模式成为可能。该RNA适体与天然NF-κB DNA靶点没有序列同源性，其结构的物理化学性质与κB DNA相似，并与p50同型二聚体上一个共同的核酸结合“共有表面”接触。
