Abstract
The arginine repressor (ArgR) from Escherichia coli regulates genes for L-arginine metabolism and is a required recombination factor for colE1 plasmid replication. Both functions require binding of L-arginine to the protein. In this work, nano-electrospray ionization time-of-flight mass spectrometry (nano-ESI-TOFMS) is used to study conformational and oligomeric states of intact ArgR and its isolated structural domains. In agreement with X-ray diffraction studies, it is shown that ArgR oligomerizes to form hexamers in both the presence and absence of L-arginine, and the basic unit of oligomerization appears to be the trimer. Higher-order assembly into dodecamers is also detected. The isolated C-terminal domain is found to associate into trimers and hexamers whereas the N-terminal domain is detected in its monomeric form. The observed species distributions suggest a role for the N-terminal domain in hexamer stabilization.
Original language | English (US) |
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Pages (from-to) | 2549-2552 |
Number of pages | 4 |
Journal | Rapid Communications in Mass Spectrometry |
Volume | 19 |
Issue number | 18 |
DOIs | |
State | Published - 2005 |
All Science Journal Classification (ASJC) codes
- Analytical Chemistry
- Spectroscopy
- Organic Chemistry