24JD
Crystal structure of the Aeropyrum pernix PCNA2 homotrimer
Summary for 24JD
| Entry DOI | 10.2210/pdb24jd/pdb |
| Descriptor | DNA polymerase sliding clamp 2, SULFATE ION (3 entities in total) |
| Functional Keywords | sliding clamp, pcna, aeropyrum pernix, dna binding protein |
| Biological source | Aeropyrum pernix |
| Total number of polymer chains | 4 |
| Total formula weight | 115747.62 |
| Authors | |
| Primary citation | Wang, T.,Ishino, S.,Ishino, Y.,Oyama, T. Crystal structures of PCNA1 and PCNA2 from Aeropyrum pernix: implications for a distorted heterotrimeric sliding clamp. Acta Crystallogr.,Sect.F, 82:216-221, 2026 Cited by PubMed Abstract: Aeropyrum pernix is a hyperthermophilic archaeon that possesses three proliferating cell nuclear antigen (PCNA) isoforms (ApePCNA1, ApePCNA2 and ApePCNA3) that form a heterotrimeric sliding clamp. To gain more detailed structural insights into this heterotrimeric assembly, we determined the crystal structures of ApePCNA1 and ApePCNA2. ApePCNA1 was crystallized under a new condition, and the 1.60 Å resolution structure revealed a unique nonproline cis-peptide bond between Arg187 and Arg188, which was not deeply discussed in a previous report. The structure of ApePCNA2 was determined at 2.17 Å resolution, and it forms a typical homotrimeric ring. In the cubic crystal form, its crystal packing shows an intriguing tetrahedral assembly of four trimers. Modeling the ApePCNA1-ApePCNA2-ApePCNA3 heterotrimer based on these structures suggests that the cis-peptide in ApePCNA1 induces significant steric hindrance at the subunit interface, leading to a symmetry-broken or distorted ring conformation rather than the canonical pseudo-threefold-symmetric assembly. PubMed: 42153239DOI: 10.1107/S2053230X26003687 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.17 Å) |
Structure validation
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