The transcriptional regulatory network of the amino acid producer Corynebacterium glutamicum

Abstract

The complete nucleotide sequence of the Corynebacterium glutamicum ATCC 13032 genome was previously determined and allowed the reliable prediction of 3002 protein-coding genes within this genome. Using computational methods, we have defined 158 genes, which form the minimal repertoire for proteins that presumably act as transcriptional regulators of gene expression. Most of these regulatory proteins have a direct role as DNA-binding transcriptional regulator, while others either have less well-defined functions in transcriptional regulation or even more general functions, such as the sigma factors. Recent advances in genome-wide transcriptional profiling of C. glutamicum generated a huge amount of data on regulation of gene expression. To understand transcriptional regulation of gene expression from the perspective of systems biology, rather than from the analysis of an individual regulatory protein, we compiled the current knowledge on the defined DNA-binding transcriptional regulators and their physiological role in modulating transcription in response to environmental signals. This comprehensive data collection provides a solid basis for database-guided reconstructions of the gene regulatory network of C. glutamicum, currently comprising 56 transcriptional regulators that exert 411 regulatory interactions to control gene expression. A graphical reconstruction revealed first insights into the functional modularity, the hierarchical architecture and the topological design principles of the transcriptional regulatory network of C. glutamicum.