PMID: 17010164 , Related PDB id: 2HAJ

Authors:

Su XC, Schaeffer PM, Loscha KV, Gan PH, Dixon NE, Otting G

Title:

Monomeric solution structure of the helicase-binding domain of Escherichia coli DnaG primase.

Journal:

FEBS J. 2006 Nov;273(21):4997-5009. Epub 2006 Sep 28.

Abstract:

DnaG is the primase that lays down RNA primers on single-stranded DNA during bacterial DNA replication. The solution structure of the DnaB-helicase-binding C-terminal domain of Escherichia coli DnaG was determined by NMR spectroscopy at near-neutral pH. The structure is a rare fold that, besides occurring in DnaG C-terminal domains, has been described only for the N-terminal domain of DnaB. The C-terminal helix hairpin present in the DnaG C-terminal domain, however, is either less stable or absent in DnaB, as evidenced by high mobility of the C-terminal 35 residues in a construct comprising residues 1-171. The present structure identifies the previous crystal structure of the E. coli DnaG C-terminal domain as a domain-swapped dimer. It is also significantly different from the NMR structure reported for the corresponding domain of DnaG from the thermophile Bacillus stearothermophilus. NMR experiments showed that the DnaG C-terminal domain does not bind to residues 1-171 of the E. coli DnaB helicase with significant affinity.