4O60
Structure of ankyrin repeat protein
Summary for 4O60
| Entry DOI | 10.2210/pdb4o60/pdb |
| Related | 4QFV |
| Descriptor | ANK-N5C-317 (2 entities in total) |
| Functional Keywords | ankyrin, designed ankyrin repeats, de novo protein |
| Biological source | synthetic construct |
| Total number of polymer chains | 2 |
| Total formula weight | 50447.65 |
| Authors | Ethayathulla, A.S.,Guan, L. (deposition date: 2013-12-20, release date: 2015-03-25, Last modification date: 2023-09-20) |
| Primary citation | Tikhonova, E.B.,Ethayathulla, A.S.,Su, Y.,Hariharan, P.,Xie, S.,Guan, L. A transcription blocker isolated from a designed repeat protein combinatorial library by in vivo functional screen. Sci Rep, 5:8070-8070, 2015 Cited by PubMed Abstract: A highly diverse DNA library coding for ankyrin seven-repeat proteins (ANK-N5C) was designed and constructed by a PCR-based combinatorial assembly strategy. A bacterial melibiose fermentation assay was adapted for in vivo functional screen. We isolated a transcription blocker that completely inhibits the melibiose-dependent expression of α-galactosidase (MelA) and melibiose permease (MelB) of Escherichia coli by specifically preventing activation of the melAB operon. High-resolution crystal structural determination reveals that the designed ANK-N5C protein has a typical ankyrin fold, and the specific transcription blocker, ANK-N5C-281, forms a domain-swapped dimer. Functional tests suggest that the activity of MelR, a DNA-binding transcription activator and a member of AraC family of transcription factors, is inhibited by ANK-N5C-281 protein. All ANK-N5C proteins are expected to have a concave binding area with negative surface potential, suggesting that the designed ANK-N5C library proteins may facilitate the discovery of binders recognizing structural motifs with positive surface potential, like in DNA-binding proteins. Overall, our results show that the established library is a useful tool for the discovery of novel bioactive reagents. PubMed: 25627011DOI: 10.1038/srep08070 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.52 Å) |
Structure validation
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