1X3U
Solution structure of the C-terminal transcriptional activator domain of FixJ from Sinorhizobium melilot
Summary for 1X3U
| Entry DOI | 10.2210/pdb1x3u/pdb |
| Descriptor | Transcriptional regulatory protein fixJ (1 entity in total) |
| Functional Keywords | helix-turn-helix, transcription |
| Biological source | Sinorhizobium meliloti |
| Cellular location | Cytoplasm (Probable): P10958 |
| Total number of polymer chains | 1 |
| Total formula weight | 8580.91 |
| Authors | Kurashima-Ito, K.,Kasai, Y.,Hosono, K.,Tamura, K.,Oue, S.,Isogai, M.,Ito, Y.,Nakamura, H.,Shiro, Y. (deposition date: 2005-05-10, release date: 2006-05-02, Last modification date: 2024-05-29) |
| Primary citation | Kurashima-Ito, K.,Kasai, Y.,Hosono, K.,Tamura, K.,Oue, S.,Isogai, M.,Ito, Y.,Nakamura, H.,Shiro, Y. Solution structure of the C-terminal transcriptional activator domain of FixJ from Sinorhizobium meliloti and its recognition of the fixK promoter Biochemistry, 44:14835-14844, 2005 Cited by PubMed Abstract: FixJ is a response regulator of the two-component signal transduction pathway involved in the transcriptional activation of nitrogen fixation genes of Sinorhizobium meliloti. Upon phosphorylation, FixJ transcriptionally activates the fixK and nifA promoters. We identified a FixJ recognition sequence of 16 bp in the high affinity binding site of the fixK promoter by means of a gel shift assay. In addition, the solution structure of the truncated C-terminal DNA binding domain of FixJ (FixJC) was solved by NMR spectroscopy. FixJC contains five alpha-helices that encode a typical helix-turn-helix motif as a potential DNA binding core with the highest structural similarity toward the C-terminal DNA binding domain of NarL. The addition of the DNA fragment containing the recognition sequence of the high affinity FixJ binding site resulted in intermediate to slow exchange interactions on the NMR time scale in the spectrum of FixJC, while the exchange was rapid in the case of control DNA. These spectral data suggest that more than one molecule of FixJC binds to the recognition sequence, although FixJC alone is present in monomeric form in solution. This result is consistent with a scenario in which a transcriptionally active species of FixJ is a homodimer of the phosphorylated form. PubMed: 16274231DOI: 10.1021/bi0509043 PDB entries with the same primary citation |
| Experimental method | SOLUTION NMR |
Structure validation
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