Transcription Initiation Complex Analyzed

A high-resolution structure of the transcription initiation complex formed by RNA polymerase, an initiation factor, and a gene promoter helps elucidate how DNA is recognized, unwound, and prepared for transcription to RNA (Science, DOI: 10.1126/science.1227786). The structure of the bacterial complex could facilitate the development of new antibacterial agents and aid understanding of transcription in higher organisms, which is structurally and mechanistically similar. The structure, obtained by Richard H. Ebright, Eddy Arnold, and coworkers at Rutgers University, includes parts of the complex never before determined at high resolution. It reveals for the first time a component of the structure called the “core recognition element,” shows more clearly than before how multiple protein pockets recognize different promoter DNA sequences, and demonstrates how such interactions “preorganize” DNA to engage with RNA polymerase’s active center to initiate transcription. The work “informs our understanding of how transcription initiation occurs and may lead to new ways to manipulate this fundamental process for therapeutic purposes,” comments Peter Preusch, who administers grants on such complexes at the National Institute of General Medical Sciences.