A Role for the Conserved GAFTGA Motif of AAA+ Transcription Activators in Sensing Promoter DNA Conformation

Transcription from σ54-dependent bacterial promoters can be regarded as a second paradigm for bacterial gene transcription. The initial σ54-RNA polymerase (RNAP)·promoter complex, the closed complex, is transcriptionally silent. The transcriptionally proficient σ54-RNAP·promoter complex, the open co...

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Bibliographic Details
Published in:The Journal of biological chemistry 2007-01, Vol.282 (2), p.1087-1097
Main Authors: Dago, Angel Ernesto, Wigneshweraraj, Siva R., Buck, Martin, Morett, Enrique
Format: Article
Language:English
Subjects:
Adenosine Triphosphate - metabolism
Amino Acid Sequence
Bacterial Proteins - genetics
Bradyrhizobium - genetics
Conserved Sequence
DNA, Bacterial - chemistry
DNA, Bacterial - genetics
Gene Expression Regulation, Bacterial
Klebsiella pneumoniae - genetics
Metalloendopeptidases - chemistry
Metalloendopeptidases - genetics
Metalloendopeptidases - metabolism
Molecular Sequence Data
Mutagenesis, Site-Directed
Nucleic Acid Conformation
Promoter Regions, Genetic - genetics
Protein Structure, Tertiary
RNA Polymerase Sigma 54 - genetics
RNA Polymerase Sigma 54 - metabolism
Sigma Factor - genetics
Sigma Factor - metabolism
Trans-Activators - chemistry
Trans-Activators - genetics
Transcription Factors - genetics
Transcriptional Activation - physiology
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Summary:Transcription from σ54-dependent bacterial promoters can be regarded as a second paradigm for bacterial gene transcription. The initial σ54-RNA polymerase (RNAP)·promoter complex, the closed complex, is transcriptionally silent. The transcriptionally proficient σ54-RNAP·promoter complex, the open complex, is formed upon remodeling of the closed complex by actions of a specialized activator protein that belongs to the AAA (ATPases associated with various cellular activities) protein family in an ATP hydrolysis-dependent reaction. The integrity of a highly conserved signature motif in the AAA activator (known as the GAFTGA motif) is important for the remodeling activity of the AAA activator and for open complex formation. We now provide evidence that the invariant threo-nine residue of the GAFTGA motif plays a role in sensing the DNA downstream of the σ54-RNAP-binding site and in coupling this information to σ54-RNAP via the conserved regulatory Region I domain of σ54 during open complex formation.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M608715200