9MJ5
Catalytic domain of human DNA polymerase alpha in complex with DNA and RPA
Summary for 9MJ5
| Entry DOI | 10.2210/pdb9mj5/pdb |
| EMDB information | 48312 |
| Descriptor | Replication protein A 14 kDa subunit, Replication protein A 32 kDa subunit, Replication protein A 70 kDa DNA-binding subunit, ... (9 entities in total) |
| Functional Keywords | dna replication, replication-dna-rna complex, replication/dna/rna |
| Biological source | Homo sapiens (human) More |
| Total number of polymer chains | 6 |
| Total formula weight | 179330.90 |
| Authors | Baranovskiy, A.G.,Morstadt, L.M.,Romero, E.E.,Babayeva, N.D.,Tahirov, T.H. (deposition date: 2024-12-13, release date: 2025-02-19, Last modification date: 2025-09-03) |
| Primary citation | Baranovskiy, A.G.,Morstadt, L.M.,Romero, E.E.,Babayeva, N.D.,Tahirov, T.H. The human primosome requires replication protein A when copying DNA with inverted repeats. Nucleic Acids Res., 53:-, 2025 Cited by PubMed Abstract: The human primosome, a four-subunit complex of primase and DNA polymerase alpha (Polα), initiates DNA synthesis on both chromosome strands by generating chimeric RNA-DNA primers for loading DNA polymerases delta and epsilon (Polϵ). Replication protein A (RPA) tightly binds to single-stranded DNA strands, protecting them from nucleolytic digestion and unauthorized transactions. We report here that RPA plays a critical role for the human primosome during DNA synthesis across inverted repeats prone to hairpin formation. On other alternatively structured DNA, forming a G-quadruplex, RPA does not assist primosome. A stimulatory effect of RPA on DNA synthesis across hairpins was also observed for the catalytic domain of Polα but not of Polϵ. The winged helix-turn-helix domain of RPA is essential for an efficient hairpin bypass and increases RPA-Polα cooperativity on the primed DNA template. Cryo-EM studies revealed that this domain is mainly responsible for the interaction between RPA and Polα. The flexible mode of RPA-Polα interaction during DNA synthesis implies the mechanism of template handover between them when the hairpin formation should be avoided. This work provides insight into a cooperative action of RPA and primosome on DNA, which is critical for DNA synthesis across inverted repeats. PubMed: 40829805DOI: 10.1093/nar/gkaf799 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.5 Å) |
Structure validation
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