MarA-mediated transcriptional repression of the rob promoter

The Escherichia coli transcriptional regulator MarA affects functions that include antibiotic resistance, persistence, and survival. MarA functions as an activator or repressor of transcription utilizing similar degenerate DNA sequences (marboxes) with three different binding site configurations with respect to the RNA polymerase-binding sites. We demonstrate that MarA down-regulates rob transcripts both in vivo and in vitro via a MarA-binding site within the rob promoter that is positioned between the -10 and -35 hexamers. As for the hdeA and purA promoters, which are repressed by MarA, the rob marbox is also in the "backward" orientation. Protein-DNA interactions show that SoxS and Rob, like MarA, bind the same marbox in the rob promoter. Electrophoretic mobility shift analyses with a MarA-specific antibody demonstrate that MarA and RNA polymerase form a ternary complex with the rob promoter DNA. Transcription experiments in vitro and potassium permanganate footprinting analysis show that MarA affects the RNA polymerase-mediated closed to open complex formation at the rob promoter.

The Escherichia coli transcriptional regulator MarA directly represses transcription of purA and hdeA

The Escherichia coli MarA protein mediates a response to multiple environmental stresses through the activation or repression in vivo of a large number of chromosomal genes. Transcriptional activation for a number of these genes has been shown to occur via direct interaction of MarA with a 20-bp degenerate asymmetric "marbox" sequence. It was not known whether repression by MarA was also direct. We found that purified MarA was sufficient in vitro to repress transcription of both purA and hdeA. Transcription and electrophoretic mobility shift experiments in vitro using mutant promoters suggested that the marbox involved in the repression overlapped the -35 promoter motif and was in the "backward" orientation. This organization contrasts with that of the class II promoters activated by MarA, in which the marbox also overlaps the -35 motif but is in the "forward" orientation. We conclude that MarA, a member of the AraC/XylS family, can act directly as a repressor or an activator, depending on the position and orientation of the marbox within a promoter.

International Coordination in Cross-Border Bank Bail-ins: Problems and Prospects

Bail-in is quickly becoming a predominant approach to banking resolution. The EU Bank Recovery Resolution Directive and the US Federal Deposit Insurance Corporation’s single point of entry strategy envisage creditors’ recapitalisations
to resolve a failing financial institution. However, this legislation focuses on the domestic aspects of bail-in, leaving the question of how it is applied
to a cross-border banking group open. Cross-border banking resolution has been historically subject to coordination failures, which have resulted in disorderly resolutions with dangerous systemic effects. The goal of this article is to assess whether bail-in is subject to the same coordination problems that affect other resolution tools, and to discuss the logic of international legal cooperation in bail-in policies. We demonstrate that, in spite of the evident benefit in terms of fiscal sustainability, bail-in suffers from complex coordination problems which, if not addressed, might lead to regulatory arbitrage and lengthy court battles, and, ultimately, may disrupt resolutions. We argue that only a binding legal regime can address those problems. In doing so, we discuss the recent Financial Stability
Board’s proposal on cross-border recognition of resolution action, and the role of international law in promoting cooperation in banking resolution.