Transcription activation by Escherichia coli Rob at class II promoters: protein-protein interactions between Rob's N-terminal domain and the σ(70) subunit of RNA polymerase
| Autor: | Richard E. Wolf, Lanyn P. Taliaferro, Neus Sanchez-Alberola, Edward F. Keen |
|---|---|
| Rok vydání: | 2011 |
| Předmět: |
Transcriptional Activation
Sigma Factor Biology Article chemistry.chemical_compound Structural Biology Transcription (biology) Bacterial transcription Sigma factor RNA polymerase Escherichia coli Binding site Promoter Regions Genetic Molecular Biology Transcription factor Genetics Binding Sites Escherichia coli Proteins Promoter DNA-Directed RNA Polymerases Gene Expression Regulation Bacterial SOXS DNA-Binding Proteins chemistry Trans-Activators Protein Binding Transcription Factors |
| Zdroj: | Journal of molecular biology. 419(3-4) |
| ISSN: | 1089-8638 |
| Popis: | Bacterial transcription activators regulate transcription by making essential protein-protein interactions with RNA polymerase, for example, with region 4 of the σ(70) subunit (σ(70) R4). Rob, SoxS, and MarA comprise a closely related subset of members of the AraC/XylS family of transcription factors that activate transcription of both class I and class II promoters. Recently, we showed that interactions between SoxS and σ(70) R4 occlude the binding of σ(70) R4 to the -35 promoter element of class II promoters. Although Rob shares many similarities with SoxS, it contains a C-terminal domain (CTD) that the other paralogs do not. Thus, a goal of this study was to determine whether Rob makes protein-protein interactions with σ(70) R4 at class II promoters and, if so, whether the interactions occlude the binding of σ(70) R4 to the -35 hexamer despite the presence of the CTD. We found that although Rob makes fewer interactions with σ(70) R4 than SoxS, the two proteins make the same, unusual, position-dependent interactions. Importantly, we found that Rob occludes σ(70) R4 from binding the -35 hexamer, just as does SoxS. Thus, the CTD does not substantially alter the way Rob interacts with σ(70) R4 at class II promoters. Moreover, in contrast to inferences drawn from the co-crystal structure of Rob bound to robbox DNA, which showed that only one of Rob's dual helix-turn-helix (HTH) DNA binding motifs binds a recognition element of the promoter's robbox, we determined that the two HTH motifs each bind a recognition element in vivo. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect