PT - JOURNAL ARTICLE AU - Buck, M. AU - Bose, D. AU - Burrows, P. AU - Cannon, W. AU - Joly, N. AU - Pape, T. AU - Rappas, M. AU - Schumacher, J. AU - Wigneshweraraj, S. AU - Zhang, X. TI - A second paradigm for gene activation in bacteria AID - 10.1042/BST0341067 DP - 2006 Dec 01 TA - Biochemical Society Transactions PG - 1067--1071 VI - 34 IP - 6 4099 - 4100 - SO - Biochem Soc Trans2006 Dec 01; 34 AB - Control of gene expression is key to development and adaptation. Using purified transcription components from bacteria, we employ structural and functional studies in an integrative manner to elaborate a detailed description of an obligatory step, the accessing of the DNA template, in gene expression. Our work focuses on a specialized molecular machinery that utilizes ATP hydrolysis to initiate DNA opening and permits a description of how the events triggered by ATP hydrolysis within a transcriptional activator can lead to DNA opening and transcription. The bacterial EBPs (enhancer binding proteins) that belong to the AAA+ (ATPases associated with various cellular activities) protein family remodel the RNAP (RNA polymerase) holoenzyme containing the σ54 factor and convert the initial, transcriptionally silent promoter complex into a transcriptionally proficient open complex using transactions that reflect the use of ATP hydrolysis to establish different functional states of the EBP. A molecular switch within the model EBP we study [called PspF (phage shock protein F)] is evident, and functions to control the exposure of a solvent-accessible flexible loop that engages directly with the initial RNAP promoter complex. The σ54 factor then controls the conformational changes in the RNAP required to form the open promoter complex.Abbreviations: AAA+, ATPases associated with various cellular activities; EBP, enhancer binding protein; PspF, phage shock protein F; RNAP, RNA polymerase