CheY is the best characterized member of the response regulator superfamily, and as such it has become the principal model for understanding the initial molecular mechanisms of signaling in two-component systems. Normal signaling by response regulators requires phosphorylation, in combination with an activation mechanism whose conformational effects are not completely understood ...
CheY is the best characterized member of the response regulator superfamily, and as such it has become the principal model for understanding the initial molecular mechanisms of signaling in two-component systems. Normal signaling by response regulators requires phosphorylation, in combination with an activation mechanism whose conformational effects are not completely understood. CheY activation involves three events, phosphorylation, a conformational change in the beta(4)--alpha(4) loop, and a rotational restriction of the side chain of tyrosine 106. An outstanding question concerns the nature of an active conformation in the apoCheY population. The details of this 1.08-A resolution crystal structure of wild-type apoCheY shows the beta(4)--alpha(4) loop in two distinctly different conformations that sterically correlate with the two rotameric positions of the tyrosine 106 side chain. One of these conformational states of CheY is the inactive form, and we propose that the other is a meta-active form, responsible for the active properties seen in apoCheY.
Related Citations:
Atomic Resolution Structure of a Succinimide Intermediate in E. coli CheY Simonovic, M., Volz, K. (2002) J Mol Biol 322: 663
Organizational Affiliation:
Department of Biochemistry and Molecular Biology, University of Illinois at Chicago, Chicago, Illinois 60612-7334, USA.
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