9EWC
DNA Polymerase Lambda I493R 528-530 NEY, TTP:At Ca2+ Ground State Ternary Complex
Summary for 9EWC
| Entry DOI | 10.2210/pdb9ewc/pdb |
| Related | 9ewb |
| Descriptor | DNA polymerase lambda, DNA template strand, DNA primer strand upstream, ... (8 entities in total) |
| Functional Keywords | dna polymerase gap filling, nuclear protein |
| Biological source | Homo sapiens (human) More |
| Total number of polymer chains | 8 |
| Total formula weight | 86603.84 |
| Authors | Nourisson, A.,Haouz, A.,Missoury, S.,Delarue, M. (deposition date: 2024-04-03, release date: 2025-07-23, Last modification date: 2025-09-10) |
| Primary citation | Nourisson, A.,Missoury, S.,Lucas-Staat, S.,Haouz, A.,Delarue, M. Fidelity, specialization, and evolution of Paramecium PolX DNA polymerases involved in programmed double-strand break DNA repair. Nucleic Acids Res., 53:-, 2025 Cited by PubMed Abstract: Repairing programmed DNA double-strand breaks (DSBs) is crucial in the lifecycle of Paramecium tetraurelia, especially during its sexual reproduction phase when its somatic polyploid macronucleus is lost. The formation of a new macronucleus involves programmed genome rearrangements, introducing DNA DSBs at ∼45 000 loci. Paramecium tetraurelia employs a non-homologous end joining (NHEJ) mechanism for the faithful repair of these DSBs. There are four genes encoding DNA polymerases of family X in the genome, one of which was found recently to colocalize with other NHEJ proteins in the nucleus. Here we have characterized all four enzymes and shown that they are generally very faithful. They fall into two functional classes that may specialize in the distinct repair contexts encountered during DSB DNA repair. Biochemical assays, site-directed mutagenesis, and X-ray structures of mutants of human Polλ incorporating sequence determinants from P. tetraurelia PolX or metazoan Polβ are used to investigate the origin of their fidelity. Our findings suggest that Paramecium PolX enzymes may represent evolutionary intermediates between metazoan Polβ and Polλ. A general classification of DNA PolXs based on clustering methods indicates that our results can be generalized to plant DNA PolXs (Polλ-like) involved in DSB DNA repair generated by CRISPR-Cas9 engineering. PubMed: 40829804DOI: 10.1093/nar/gkaf786 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (3.67 Å) |
Structure validation
Download full validation report
