32KS
Cryo-EM structure of full-length ComEC from Neomoorella carbonis
This is a non-PDB format compatible entry.
Summary for 32KS
| Entry DOI | 10.2210/pdb32ks/pdb |
| Related | 30BT 30BU |
| EMDB information | 57548 57549 |
| Descriptor | ComEC (1 entity in total) |
| Functional Keywords | dna translocation, nuclease, dna binding, membrane protein |
| Biological source | Neomoorella carbonis |
| Total number of polymer chains | 2 |
| Total formula weight | 175329.83 |
| Authors | Deselaers, S.,Wang, D.,Cairoli, T.,Afanasyev, P.,Hospenthal, M.K. (deposition date: 2026-07-14, release date: 2026-08-05, Last modification date: 2026-09-16) |
| Primary citation | Deselaers, S.,Wang, D.,Cairoli, T.,Afanasyev, P.,Hospenthal, M.K. Structure and biochemistry reveal substrate-modulated ComEC nuclease activity during DNA processing. Nucleic Acids Res., 54:-, 2026 Cited by PubMed Abstract: Natural transformation enables bacteria to internalize extracellular DNA, driving adaptation and the spread of antibiotic resistance. The membrane protein ComEC mediates translocation of single-stranded DNA (ssDNA) across the cytoplasmic membrane while degrading the complementary strand, yet the structural basis of its activity remains incompletely defined. Here, we report a cryo-electron microscopy structure of full-length ComEC from Neomoorella carbonis in a pre-translocation state, revealing a three-domain architecture and a conserved transmembrane channel captured in a closed conformation. Structural analysis indicates that conformational rearrangements of channel-lining helices would be required to accommodate ssDNA. Biochemical assays show that, relative to the isolated β-lactamase-like domain, full-length ComEC degrades DNA more efficiently and exhibits position-dependent cleavage of phosphodiester bonds within the DNA substrate. Importantly, coating of the DNA by the periplasmic DNA receptor ComEA suppresses endonucleolytic cleavage and enhances 5'' terminal cleavage, thereby directing ComEC towards productive processing of transforming DNA during natural transformation. PubMed: 42689412DOI: 10.1093/nar/gkag861 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (4.1 Å) |
Structure validation
Download full validation report
