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Monomeric solution structure of the helicase‐binding domain of Escherichia coli DnaG primase
Author(s) -
Su XunCheng,
Schaeffer Patrick M.,
Loscha Karin V.,
Gan Pamela H. P.,
Dixon Nicholas E.,
Otting Gottfried
Publication year - 2006
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/j.1742-4658.2006.05495.x
Subject(s) - dnab helicase , dnag , primase , escherichia coli , helicase , dna , chemistry , biology , crystallography , biochemistry , dna replication , rna , gene , circular bacterial chromosome , reverse transcriptase
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.