DksA regulates RNA polymerase in Escherichia coli through a network of interactions in the secondary channel that includes Sequence Insertion 1

作者：Parshin Andrey; Shiver Anthony L; Lee Jookyung; Ozerova Maria; Schneidman Duhovny Dina; Gross Carol A^*; Borukhov Sergei

来源：Proceedings of the National Academy of Sciences, 2015, 112(50): E6862-E6871.

DOI：10.1073/pnas.1521365112

• transcription regulation
• stringent response
• protein cross-linking
• molecular modeling
• lineage-specific insertions

Sensing and responding to nutritional status is a major challenge for microbial life. In Escherichia coli, the global response to amino acid starvation is orchestrated by guanosine-3',5'-bisdiphosphate and the transcription factor DksA. DksA alters transcription by binding to RNA polymerase and allosterically modulating its activity. Using genetic analysis, photo-cross-linking, and structural modeling, we show that DksA binds and acts upon RNA polymerase through prominent features of both the nucleotide-access secondary channel and the active-site region. This work is, to our knowledge, the first demonstration of a molecular function for Sequence Insertion 1 in the beta subunit of RNA polymerase and significantly advances our understanding of how DksA binds to RNA polymerase and alters transcription.

• 出版日期2015-12-15