1JE5

Crystal Structure of gp2.5, a Single-Stranded DNA Binding Protein Encoded by Bacteriophage T7

Summary for 1JE5

• Entry DOI: 10.2210/pdb1je5/pdb
• Descriptor: HELIX-DESTABILIZING PROTEIN, CALCIUM ION (3 entities in total)
• Functional Keywords: ob-fold, beta barrel, dna binding protein
• Biological source: Enterobacteria phage T7
• Total number of polymer chains: 2
• Total formula weight: 45461.61

Authors

Hollis, T.,Stattel, J.M.,Walther, D.S.,Richardson, C.C.,Ellenberger, T.E. (deposition date: 2001-06-15, release date: 2001-08-22, Last modification date: 2024-02-07)

Primary citation

Hollis, T.,Stattel, J.M.,Walther, D.S.,Richardson, C.C.,Ellenberger, T.
Structure of the gene 2.5 protein, a single-stranded DNA binding protein encoded by bacteriophage T7.
Proc.Natl.Acad.Sci.USA, 98:9557-9562, 2001

PubMed Abstract: The gene 2.5 protein (gp2.5) of bacteriophage T7 is a single-stranded DNA (ssDNA) binding protein that has essential roles in DNA replication and recombination. In addition to binding DNA, gp2.5 physically interacts with T7 DNA polymerase and T7 primase-helicase during replication to coordinate events at the replication fork. We have determined a 1.9-A crystal structure of gp2.5 and show that it has a conserved OB-fold (oligosaccharide/oligonucleotide binding fold) that is well adapted for interactions with ssDNA. Superposition of the OB-folds of gp2.5 and other ssDNA binding proteins reveals a conserved patch of aromatic residues that stack against the bases of ssDNA in the other crystal structures, suggesting that gp2.5 binds to ssDNA in a similar manner. An acidic C-terminal extension of the gp2.5 protein, which is required for dimer formation and for interactions with the T7 DNA polymerase and the primase-helicase, appears to be flexible and may act as a switch that modulates the DNA binding affinity of gp2.5.

PubMed: 11481454
DOI: 10.1073/pnas.171317698

Experimental method

X-RAY DIFFRACTION (1.9 Å)