Crystal structure of hypothetical protein TTHB210, controlled by the σ E/anti-σ E regulatory system in Thermus thermophilus HB8, reveals a novel homodecamer

摘要

The bacterial RNA polymerase (RNAP) core enzyme, with the subunit structure alpha_2 beta beta, binds a factor, which is responsible for promoter recognition and selectivity. Most bacteria have a primary factor that recognizes the majority of the genes, and several alternative a factors that recognize the promoters of specialized regulons, such as those involved in growth transitions, morphological changes, responses to environmental stress conditions, and pathogens.1 Extracytoplasmic function (ECF) factors are alternative a factors, and many of them control the transcription of various genes involved in cell envelope functions and extracytoplasmic stress conditions.2 In many cases, an ECF a factor is co-transcribed with a transmembrane anti-cr factor with an extracytoplasmic sensor domain and an intracellular inhibiting domain, which negatively regulates the activity of the ECF factor.