1NUI

Crystal Structure of the primase fragment of Bacteriophage T7 primase-helicase protein

Summary for 1NUI

• Entry DOI: 10.2210/pdb1nui/pdb
• Descriptor: DNA primase/helicase, ZINC ION, MAGNESIUM ION, ... (4 entities in total)
• Functional Keywords: zinc-biding domain, toprim fold, dna replication, dna-directed rna polymerase, primosome, late protein, atp-binding, transferase, replication
• Biological source: Enterobacteria phage T7
• Total number of polymer chains: 2
• Total formula weight: 57029.66

Authors

Kato, M.,Ito, T.,Wagner, G.,Richardson, C.C.,Ellenberger, T. (deposition date: 2003-01-31, release date: 2003-05-27, Last modification date: 2024-02-14)

Primary citation

Kato, M.,Ito, T.,Wagner, G.,Richardson, C.C.,Ellenberger, T.
Modular Architecture of the Bacteriophage T7 Primase Couples RNA primer Synthesis to DNA Synthesis
Mol.Cell, 11:1349-1360, 2003

PubMed Abstract: DNA primases are template-dependent RNA polymerases that synthesize oligoribonucleotide primers that can be extended by DNA polymerase. The bacterial primases consist of zinc binding and RNA polymerase domains that polymerize ribonucleotides at templating sequences of single-stranded DNA. We report a crystal structure of bacteriophage T7 primase that reveals its two domains and the presence of two Mg(2+) ions bound to the active site. NMR and biochemical data show that the two domains remain separated until the primase binds to DNA and nucleotide. The zinc binding domain alone can stimulate primer extension by T7 DNA polymerase. These findings suggest that the zinc binding domain couples primer synthesis with primer utilization by securing the DNA template in the primase active site and then delivering the primed DNA template to DNA polymerase. The modular architecture of the primase and a similar mechanism of priming DNA synthesis are likely to apply broadly to prokaryotic primases.

PubMed: 12769857
DOI: 10.1016/S1097-2765(03)00195-3

Experimental method

X-RAY DIFFRACTION (2.9 Å)