Chalissery, J. and Muteeb, G. and Kalarickal, N.C. and Shalini, M. and Jisha, V. and Sen, Ranjan (2011) Interaction Surface of the Transcription Terminator Rho Required to Form a Complex with the C-Terminal Domain of the Antiterminator NusG. Journal of Molecular Biology, 405 (1). pp. 49-64. ISSN 0022-2836

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Abstract

Rho-dependent transcription termination in bacteria requires an interaction between the terminator Rho and the antiterminator NusG. The interaction surface of the Rho-NusG complex is unknown. Here we provide direct evidence that the β-sheet bundle of the C-terminal domain of NusG (NusG-CTD) has the binding determinants for Rho, proving the hypothesis described earlier [Mooney, R. A., Schweimer, K., Rosch, P., Gottesman, M., & Landick, R., (2009). Two structurally independent domains of E. coli NusG create regulatory plasticity via distinct interactions with RNA polymerase and regulators. J. Mol. Biol., 391, 341-358.]. Disulfide bridges can be engineered from NusG-CTD with the surface-exposed amino acids 217 and 224 of Rho, which belong to its P-loop ATPase domain. Mutational analyses of this region of Rho revealed that a hydrophobic pocket, located behind these amino acids of Rho, is the docking site for NusG-CTD. The proximity of this region of Rho to NusG-CTD in the Rho-NusG complex was also confirmed by an efficient fluorescence resonance energy transfer between residue K224 of Rho and residue A168 of NusG-CTD. The identification of the Rho-NusG interaction surface will be useful not only in understanding the role of NusG in the termination process but also in explaining the molecular basis of the involvement of NusG-CTD in recruiting Rho and the ribosome to the same transcription machinery.

Item Type:	Article
Depositing User:	Users 2 not found.
Date Deposited:	02 Sep 2015 07:29
Last Modified:	02 Sep 2015 07:29
URI:	http://cdfd.sciencecentral.in/id/eprint/444

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