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Escherichia coli single-stranded DNA-binding protein: nanoESI-MS studies of salt-modulated subunit exchange and DNA binding transactions
Faculty of Science, Medicine and Health - Papers
  • Claire E Mason, University of Wollongong
  • Slobodan Jergic, University of Wollongong
  • Allen Lo, University of Wollongong
  • Yao Wang, University of Wollongong
  • Nicholas E Dixon, University of Wollongong
  • Jennifer L Beck, University of Wollongong
RIS ID
76235
Publication Date
1-1-2013
Publication Details

Mason, C. E., Jergic, S., Lo, A., Wang, Y., Dixon, N. E. & Beck, J. L. (2013). Escherichia coli single-stranded DNA-binding protein: nanoESI-MS studies of salt-modulated subunit exchange and DNA binding transactions. Journal of the American Society for Mass Spectrometry, 24 (2), 274-285.

Abstract

Single-stranded DNA-binding proteins (SSBs) are ubiquitous oligomeric proteins that bind with very high affinity to single-stranded DNA and have a variety of essential roles in DNA metabolism. Nanoelectrospray ionization mass spectrometry (nanoESI-MS) was used to monitor subunit exchange in full-length and truncated forms of the homotetrameric SSB from Escherichia coli. Subunit exchange in the native protein was found to occur slowly over a period of hours, but was significantly more rapid in a truncated variant of SSB from which the eight C-terminal residues were deleted. This effect is proposed to result from C-terminus mediated stabilization of the SSB tetramer, in which the C-termini interact with the DNA-binding cores of adjacent subunits. NanoESI-MS was also used to examine DNA binding to the SSB tetramer. Binding of single-stranded oligonucleotides [one molecule of (dT)70, one molecule of (dT)35, or two molecules of (dT)35] was found to prevent SSB subunit exchange. Transfer of SSB tetramers between discrete oligonucleotides was also observed and is consistent with predictions from solution-phase studies, suggesting that SSB-DNA complexes can be reliably analyzed by ESI mass spectrometry.

Citation Information
Claire E Mason, Slobodan Jergic, Allen Lo, Yao Wang, et al.. "Escherichia coli single-stranded DNA-binding protein: nanoESI-MS studies of salt-modulated subunit exchange and DNA binding transactions" (2013)
Available at: http://works.bepress.com/nick_dixon/86/