Antibiotics Resistance 2018: Lethal effect of denatured ribosome recycling factor at lag phase- Hideko Kaji, Thomas Jefferson University | Abstract

Advances in Antibiotics & Antibodies


Antibiotics Resistance 2018: Lethal effect of denatured ribosome recycling factor at lag phase- Hideko Kaji, Thomas Jefferson University

Author(s): Hideko Kaji

Ribosome recycling factor (RRF) is an essential protein factor responsible for disassembly of the post-termination complex. Protein synthesis consists of four steps, initiation, elongation of peptide chain, termination and the ribosome recycling step. RRF catalyzes the fourth step of protein synthesis in bacteria. It was known that inactivation of temperature sensitive RRF (tsRRF) at lag phase resulted in lethal effect (Janosi, Mottagui-Tabar et al. 1998) while at log and stationary phase it has bacteriostatic effect. In this paper, we tried to elucidate the beginning of physiological and cellular changes due to the inactivation of RRF so that we have a glimpse of the possible mechanism of lethal effect of inactivation of tsRRF at lag phase only. We found under the condition where the lethal effect is observed that a large amount of 40S particles were formed containing 16S rRNA. Within hour of the appearance of this 40S particles cells start dying. Measures such as inhibition of protein chain elongation stopped the lethal effect of tsRRF at the non-permissive temperature. All such measures eliminated the appearance of the 40S particles. We conclude that the 40S particle is essential for lethal effect of tsRRF at the lag phase. Our proteomics data showed upregulation of alternate ribosome rescue factor (ArfA) at the non-permissive temperature provide evidence about RRF essentiality. Effect of various antibiotics on the formation of the 40S particles and on the lethal effect of tsRRF will be described.

We have disengaged a protein, develop RRFHCP, from chloroplasts of spinach (Spinacia oleracea L.) that shows 46% arrangement character and 66% grouping homology with ribosome reusing factor (RRF) of Escherichia coli. RRF reuses ribosomes through dismantling of the posttermination complex. From the cDNA investigation and from the amino-terminal sequencing of the disengaged protein, the develop RRFHCP was reasoned to have a Mr of 21,838 with 193 aa. It comes up short on the 78-aa chloroplast focusing on succession encoded by the RRFHCP cDNA grouping. The RRFHCP blended in vitro was brought into confined chloroplasts with synchronous change to the develop RRFHCP. Interpretation of the quality coding for RRFHCP was not reliant on light, yet it was constrained for the most part to photosynthetic tissues in which just a single transcript size was identified. Develop RRFHCP applied a bactericidal impact on E. coli conveying temperature-touchy RRF at the lenient temperature though wild-type E. coli was not influenced.


The plant chloroplast translational framework is like the prokaryotic one, in that chloroplasts and bacterial ribosomes have regular highlights, and are delicate to similar anti-infection agents. Chloroplast mRNAs are like that of prokaryotes in that they are not m7G-topped and can be polycistronic . Just a couple of chloroplast protein blend factors, similar to the lengthening factor G (EF-G) homologue (7, 8), have been portrayed. No data is accessible about dismantling of the post-end complex of chloroplast ribosomes.

In microscopic organisms, in spite of various examinations on interpretation, the significance of dismantling of the post-end complex of ribosomes has been disregarded. Two elements are important for the dismantling of the post-end complex: ribosome reusing factor (RRF) and either EF-G  or discharge factor 3 . RRF, which is fundamental for microscopic organisms , was purged and cloned , and its qualities have been investigated. RRF expanded interpretation 4-to 8-crease by reusing ribosomes starting with one round of interpretation then onto the next . Inactivation of RRF in vivo is bactericidal or bacteriostatic relying upon the development stage. Each prokaryote genome sequenced so far has the RRF quality (frr) homologue with the exception of those having a place with Archae. Mycoplasma genitalium, the littlest free-living creature, holds RRF, proposing a key job of this factor for bacterial life.

We report here the portrayal of an atomic encoded RRF homologue in a plant. The spinach RRF homologue (RRFHCP) is handled to develop RRFHCP, which is a chloroplast protein. Transcripts of frrhcp (RRFHCP quality) were found in photosynthetic tissues, yet interpretation was not light-reliant. The statement of frrhcp in an Escherichia coli freak with temperature-touchy RRF was bactericidal even at the lenient temperature while it had no impact on the wild-type E. coli. This portrayal of an "inhibitor" of prokaryotic RRF proposes that develop RRFHCP may work in the reusing of ribosomes in chloroplasts in a manner like prokaryotic RRF.

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