TY - JOUR
T1 - Asymmetric allosteric activation of the symmetric ArgR hexamer
AU - Jin, Lihua
AU - Xue, Wei Feng
AU - Fukayama, June Wong
AU - Yetter, Jaclyn
AU - Pickering, Michael
AU - Carey, Jannette
PY - 2005/2/11
Y1 - 2005/2/11
N2 - Hexameric arginine repressor, ArgR, bound to l-arginine serves both as the master transcriptional repressor/activator at diverse regulons in a wide range of bacteria and as a required cofactor for resolution of ColE1 plasmid multimers. Multifunctional ArgR is thus unusual in possessing features of specific gene regulators, global regulators, and non-specific gene organizers; its closest functional analog is probably CAP, the cyclic AMP receptor/activator protein. Isothermal titration calorimetry, surface plasmon resonance, and proteolysis indicate that binding of a single l-arginine residue per ArgR hexamer triggers a global conformational change and resets the affinities of the remaining five sites, making them 100-fold weaker. The analysis suggests a novel thermodynamic signature for this mechanism of activation.
AB - Hexameric arginine repressor, ArgR, bound to l-arginine serves both as the master transcriptional repressor/activator at diverse regulons in a wide range of bacteria and as a required cofactor for resolution of ColE1 plasmid multimers. Multifunctional ArgR is thus unusual in possessing features of specific gene regulators, global regulators, and non-specific gene organizers; its closest functional analog is probably CAP, the cyclic AMP receptor/activator protein. Isothermal titration calorimetry, surface plasmon resonance, and proteolysis indicate that binding of a single l-arginine residue per ArgR hexamer triggers a global conformational change and resets the affinities of the remaining five sites, making them 100-fold weaker. The analysis suggests a novel thermodynamic signature for this mechanism of activation.
UR - http://www.scopus.com/inward/record.url?scp=12344307390&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=12344307390&partnerID=8YFLogxK
U2 - 10.1016/j.jmb.2004.11.031
DO - 10.1016/j.jmb.2004.11.031
M3 - Article
C2 - 15663926
AN - SCOPUS:12344307390
VL - 346
SP - 43
EP - 56
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 1
ER -