NELF-E RRM Undergoes Major Structural Changes in Flexible Protein Regions on Target RNA BindingRao, J.N., Schweimer, K., Wenzel, S., Wohrl, B.M., Rosch, P.
(2008) Biochemistry 47: 3756-3761
- PubMed: 18303858
- DOI: 10.1021/bi702429m
- PubMed Abstract:
The E subunit of the human heterotetrameric negative transcription elongation factor (NELF-E) contains a canonical betaalphabetabetaalphabeta RNA recognition motif (RRM) that binds to a wide variety of RNA sequences. These induce very similar conform ...
The E subunit of the human heterotetrameric negative transcription elongation factor (NELF-E) contains a canonical betaalphabetabetaalphabeta RNA recognition motif (RRM) that binds to a wide variety of RNA sequences. These induce very similar conformational changes in the RRM as determined by nuclear magnetic resonance spectroscopy. Although the RNA binding interface of a canonical RRM is mainly located at its beta-sheet surface, for NELF-E RRM large chemical shift perturbations are observed for residues in the flexible C-terminal region and the loop between beta 3 and alpha 2, and both regions are distant from the interface. We determined the solution structure of single-stranded transactivator responsive element (TAR) RNA-bound NELF-E RRM. This structure clearly shows that RNA binding to NELF-E RRM induces formation of a helix in the C-terminus. The RNA-bound form of NELF-E RRM is very similar to the RNA-bound form of U1A RRM, although the C-terminus of the NELF-E RRM is unstructured in the free protein, whereas it is helical in the U1A protein. Thus, RNA binding to NELF-E RRM induces a conformational change toward the U1A structure, resulting in highly similar RNA binding conformations for both proteins.
Lehrstuhl Biopolymere and Research Center for Bio-Macromolecules, Universität Bayreuth, 95440 Bayreuth, Germany.