Illuminating the function of a master regulator of Caulobacter crescentus gene expression

Abstract

Bacteria must allocate cellular resources required for transcription in a manner that accommodates the temporally regulated expression of functionally specialized gene products and the constitutive synthesis of stable RNAs required for ribosome biogenesis and translation. The Caulobacter crescentus cell cycle has been well-characterized and represents a powerful model system for studying the regulation of global gene expression patterns and "just-in-time" transcription. Here, we provide evidence that the Caulobacter GcrA protein directly regulates transcription at active promoters of highly expressed genes, particularly those encoding stable RNAs. Furthermore, we demonstrate that GcrA chromosome occupancy is dynamic and subject to epigenetic regulation. Our findings establish GcrA as an integral regulator of bacterial physiology and development.