Abstract
Transcription-termination factor rho of Escherichia coli functions as an RNA-dependent ATPase that causes transcript release at specific rho-dependent termination sites on the DNA template. Rho exists as a hexagon of identical subunits, physically organized as a trimer of dimers with D3 symmetry. The structural asymmetry of the dimer is reflected in the binding properties of rho; each dimer has a strong and a weak binding site for both the ATP substrate and the RNA cofactor. Here we use homopolynucleotides in competition and complementation experiments to characterize the ATPase activation properties of the cofactor binding sites of the functional rho dimer. We show that (i) no ATPase activity is observed unless both the high- and the low-affinity cofactor binding sites of the functional rho dimer are occupied; (ii) saturating levels of poly(rC), poly(rC) in combination with poly(rU), or poly(rU) alone can fully activate the ATPase of rho; and (iii) poly(dC) can serve as a fully competitive inhibitor of half of the ATPase activity of rho when one of the cofactor sites is filled with poly(rC). These observations lead to a set of phenomenological rules that describe the cofactor dependence of the ATPase activation of the functional dimer of rho and help to define a mechanistic basis for interpreting rho function in termination.
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- Bear D. G., Hicks P. S., Escudero K. W., Andrews C. L., McSwiggen J. A., von Hippel P. H. Interactions of Escherichia coli transcription termination factor rho with RNA. II. Electron microscopy and nuclease protection experiments. J Mol Biol. 1988 Feb 20;199(4):623–635. doi: 10.1016/0022-2836(88)90306-3. [DOI] [PubMed] [Google Scholar]
- Bear D. G., Peabody D. S. The E. coli Rho protein: an ATPase that terminates transcription. Trends Biochem Sci. 1988 Sep;13(9):343–347. doi: 10.1016/0968-0004(88)90104-1. [DOI] [PubMed] [Google Scholar]
- Dombroski A. J., Platt T. Structure of rho factor: an RNA-binding domain and a separate region with strong similarity to proven ATP-binding domains. Proc Natl Acad Sci U S A. 1988 Apr;85(8):2538–2542. doi: 10.1073/pnas.85.8.2538. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Finger L. R., Richardson J. P. Stabilization of the hexameric form of Escherichia coli protein rho under ATP hydrolysis conditions. J Mol Biol. 1982 Mar 25;156(1):203–219. doi: 10.1016/0022-2836(82)90467-3. [DOI] [PubMed] [Google Scholar]
- Geiselmann J., Seifried S. E., Yager T. D., Liang C., von Hippel P. H. Physical properties of the Escherichia coli transcription termination factor rho. 2. Quaternary structure of the rho hexamer. Biochemistry. 1992 Jan 14;31(1):121–132. doi: 10.1021/bi00116a018. [DOI] [PubMed] [Google Scholar]
- Geiselmann J., Yager T. D., Gill S. C., Calmettes P., von Hippel P. H. Physical properties of the Escherichia coli transcription termination factor rho. 1. Association states and geometry of the rho hexamer. Biochemistry. 1992 Jan 14;31(1):111–121. doi: 10.1021/bi00116a017. [DOI] [PubMed] [Google Scholar]
- Geiselmann J., Yager T. D., von Hippel P. H. Functional interactions of ligand cofactors with Escherichia coli transcription termination factor rho. II. Binding of RNA. Protein Sci. 1992 Jul;1(7):861–873. doi: 10.1002/pro.5560010704. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Geiselmann J., von Hippel P. H. Functional interactions of ligand cofactors with Escherichia coli transcription termination factor rho. I. Binding of ATP. Protein Sci. 1992 Jul;1(7):850–860. doi: 10.1002/pro.5560010703. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gogol E. P., Seifried S. E., von Hippel P. H. Structure and assembly of the Escherichia coli transcription termination factor rho and its interaction with RNA. I. Cryoelectron microscopic studies. J Mol Biol. 1991 Oct 20;221(4):1127–1138. doi: 10.1016/0022-2836(91)90923-t. [DOI] [PubMed] [Google Scholar]
- Lowery C., Richardson J. P. Characterization of the nucleoside triphosphate phosphohydrolase (ATPase) activity of RNA synthesis termination factor p. II. Influence of synthetic RNA homopolymers and random copolymers on the reaction. J Biol Chem. 1977 Feb 25;252(4):1381–1385. [PubMed] [Google Scholar]
- McSwiggen J. A., Bear D. G., von Hippel P. H. Interactions of Escherichia coli transcription termination factor rho with RNA. I. Binding stoichiometries and free energies. J Mol Biol. 1988 Feb 20;199(4):609–622. doi: 10.1016/0022-2836(88)90305-1. [DOI] [PubMed] [Google Scholar]
- Mott J. E., Grant R. A., Ho Y. S., Platt T. Maximizing gene expression from plasmid vectors containing the lambda PL promoter: strategies for overproducing transcription termination factor rho. Proc Natl Acad Sci U S A. 1985 Jan;82(1):88–92. doi: 10.1073/pnas.82.1.88. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Richardson J. P. Activation of rho protein ATPase requires simultaneous interaction at two kinds of nucleic acid-binding sites. J Biol Chem. 1982 May 25;257(10):5760–5766. [PubMed] [Google Scholar]
- Richardson J. P. Rho-dependent transcription termination. Biochim Biophys Acta. 1990 Apr 6;1048(2-3):127–138. doi: 10.1016/0167-4781(90)90048-7. [DOI] [PubMed] [Google Scholar]
- Seifried S. E., Bjornson K. P., von Hippel P. H. Structure and assembly of the Escherichia coli transcription termination factor rho and its interactions with RNA. II. Physical chemical studies. J Mol Biol. 1991 Oct 20;221(4):1139–1151. doi: 10.1016/0022-2836(91)90924-u. [DOI] [PubMed] [Google Scholar]
- Seifried S. E., Wang Y., von Hippel P. H. Fluorescent modification of the cysteine 202 residue of Escherichia coli transcription termination factor rho. J Biol Chem. 1988 Sep 25;263(27):13511–13514. [PubMed] [Google Scholar]