9DVS
CryoEM structure of Syn7942 RNAP-SigA holoenzyme
Summary for 9DVS
| Entry DOI | 10.2210/pdb9dvs/pdb |
| EMDB information | 47221 47222 47223 47312 |
| Descriptor | Non-template DNA, ZINC ION, Template DNA, ... (10 entities in total) |
| Functional Keywords | siga, rnap, tac, dna binding protein, dna binding protein-dna complex, dna binding protein/dna |
| Biological source | Synechococcus elongatus More |
| Total number of polymer chains | 9 |
| Total formula weight | 469755.90 |
| Authors | Fang, M.,Gu, Y.,Matyszewski, M.,Leanca, M.,LiWang, A.,Yuzenkova, Y.,Corbett, K.D.,Golden, S.E. (deposition date: 2024-10-08, release date: 2025-10-15, Last modification date: 2026-03-04) |
| Primary citation | Fang, M.,Gu, Y.,Leanca, M.,Matyszewski, M.,LiWang, A.,Yuzenkova, Y.,Corbett, K.D.,Golden, S.S. Mechanism and reconstitution of circadian transcription in cyanobacteria. Nat.Struct.Mol.Biol., 33:275-281, 2026 Cited by PubMed Abstract: Circadian biological clocks evolved across kingdoms of life as an adaptation to predictable cycles of sunrise and sunset. In the cyanobacterium Synechococcus elongatus, a protein-based clock precisely controls when different genes are turned on and off during the 24-h day but the phasing mechanism remains unclear. Here we show the molecular basis of this regulation and reconstitute clock-controlled transcription in vitro using purified components. Biochemical and structural analyses revealed that the clock-regulated transcription factor RpaA can function as either an activator or a repressor of cyanobacterial RNA polymerase, depending on its binding position relative to core promoter elements. Leveraging the repressor mechanism, we developed a heterologous in vitro system driven by bacteriophage T7 RNA polymerase that sustains circadian transcription for multiple days. These findings explain how a single clock output generates opposite phases of gene expression and define the minimal components for circadian clock function, enabling synthetic or biotechnological applications. PubMed: 41667880DOI: 10.1038/s41594-025-01740-0 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (2.5 Å) |
Structure validation
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