5EXR

Crystal structure of human primosome

Summary for 5EXR

• Entry DOI: 10.2210/pdb5exr/pdb
• Descriptor: DNA primase small subunit, DNA primase large subunit, DNA polymerase alpha catalytic subunit, ... (6 entities in total)
• Functional Keywords: human primosome, complex, primase, dna polymerase alpha, primer, dna replication, dna, rna, replicase, replication
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 8
• Total formula weight: 609225.83

Authors

Tahirov, T.H.,Baranovskiy, A.G.,Babayeva, N.D. (deposition date: 2015-11-24, release date: 2016-03-23, Last modification date: 2024-10-16)

Primary citation

Baranovskiy, A.G.,Babayeva, N.D.,Zhang, Y.,Gu, J.,Suwa, Y.,Pavlov, Y.I.,Tahirov, T.H.
Mechanism of Concerted RNA-DNA Primer Synthesis by the Human Primosome.
J.Biol.Chem., 291:10006-10020, 2016

PubMed Abstract: The human primosome, a 340-kilodalton complex of primase and DNA polymerase α (Polα), synthesizes chimeric RNA-DNA primers to be extended by replicative DNA polymerases δ and ϵ. The intricate mechanism of concerted primer synthesis by two catalytic centers was an enigma for over three decades. Here we report the crystal structures of two key complexes, the human primosome and the C-terminal domain of the primase large subunit (p58C) with bound DNA/RNA duplex. These structures, along with analysis of primase/polymerase activities, provide a plausible mechanism for all transactions of the primosome including initiation, elongation, accurate counting of RNA primer length, primer transfer to Polα, and concerted autoregulation of alternate activation/inhibition of the catalytic centers. Our findings reveal a central role of p58C in the coordinated actions of two catalytic domains in the primosome and ultimately could impact the design of anticancer drugs.

PubMed: 26975377
DOI: 10.1074/jbc.M116.717405

Experimental method

X-RAY DIFFRACTION (3.6 Å)