Effects of N-terminal deletions of the Escherichia coli protein Fis on growth rate, tRNA 2 Ser expression and cell morphology

Abstract

The Escherichia coli Fis protein is known to be involved in a variety of processes, including the activation of stable RNA operons. In this paper we study the ability of a set of N-terminal Fis deletion mutants to stimulate transcription of the tRNA(2Ser) gene. The results indicate that the domain of the Fis protein containing residues 1-26 is not required for transcription activation. The Fis mutants that are still active in transcription stimulation can also complement the reduced growth rates of Fis- cells, suggesting that the same activating domain is involved in this phenomenon. In addition, we show that in fast growing cultures in the absence of an active Fis protein, minicells are formed. These minicells seem to arise from septum formation near the cell poles. Suppression of minicell formation by Fis also does not require the presence of the N-terminal domain of the protein.

Gin mutants that can be suppressed by a Fis-independent mutation

“…pGP1161 was used for the overproduction of Fis. In this plasmid, fis is under control of the T7 promoter on a pET11 derivative (32).…”

Variable Structures of Fis-DNA Complexes Determined by Flanking DNA – Protein Contacts

“…Like other NAPS, it also participates in many other reactions including other specialized recombination processes (e.g. in phage l excision; Thompson et al, 1987;Ball & Johnson, 1991), as a transcriptional activator of a variety of promoters (Nilsson et al, 1990;Ross et al, 1990;Xu & Johnson, 1995c), as a transcriptional repressor of a variety of promoters Ball et al, 1992;Xu & Johnson, 1995a), in DNA replication at oriC (Gille et al, 1991;Filutowicz et al, 1992), and in chromosome segregation/cell division (Paull & Johnson, 1995;Spaeny-Dekking et al, 1995). Biochemical and mutational analyses indicate that the mechanisms by which Fis functions in these varied biological roles differ, but, in many cases, one or more Fis dimers are assembled into multi-component nucleoprotein structures that involve significant DNA bending.…”

FIS modulates growth phase‐dependent topological transitions of DNA in Escherichia coli

“…Recent studies reveal FIS as a general regulator of cellular metabolism (Xu and Johnson, 1995;Gonzá lez-Gil et al, 1996). Furthermore, fis cells have reduced growth rates and also show morphological abnormalities (Filutowicz et al, 1992;Spaeny-Dekking et al, 1995). The key to the understanding of the pleiotropic effect of FIS might lie in its ability to bind and bend DNA at many non-specific sites (Betermier et al, 1994;Pan et al, 1996).…”