scholarly journals Improved Production of Enzymes, Which Are Expressed under the Pho Regulon Promoter, in thermfGene (encoding ribosome modulation factor) Disruptant ofEscherichia coli

2006 ◽  
Vol 70 (4) ◽  
pp. 949-957 ◽  
Author(s):  
Akira IMAIZUMI ◽  
Chie KOSEKI ◽  
Kazuhiko MATSUI ◽  
Hiroyuki KOJIMA
Keyword(s):  
Ofescherichia Coli ◽  
Pho Regulon ◽  
Modulation Factor ◽  
Ribosome Modulation Factor

scholarly journals Modulation of mRNA Stability Participates in Stationary-Phase-Specific Expression of Ribosome Modulation Factor

2005 ◽  
Vol 187 (6) ◽  
pp. 1951-1958 ◽  
Author(s):  
Toshiko Aiso ◽  
Hideji Yoshida ◽  
Akira Wada ◽  
Reiko Ohki
Keyword(s):  
Stationary Phase ◽  
Growth Phase ◽  
Mrna Stability ◽  
De Novo ◽  
Fresh Medium ◽  
Specific Expression ◽  
Modulation Factor ◽  
Inactive Form ◽  
Regulation Of Growth ◽  
Ribosome Modulation Factor

ABSTRACT The expression of ribosome modulation factor (RMF) is induced during stationary phase in Escherichia coli. RMF participates in the dimerization of 70S ribosomes to form the 100S ribosome, which is the translationally inactive form of the ribosome. To elucidate the involvement of the control of mRNA stability in growth-phase-specific rmf expression, we investigated rmf mRNA stability in stationary-phase cells and cells inoculated into fresh medium. The rmf mRNA was found to have an extremely long half-life during stationary phase, whereas destabilization of this mRNA took place after the culture was inoculated into fresh medium. RMF and 100S ribosomes disappeared from cells 1 min after inoculation. In addition to control by ppGpp-dependent transcription, these results indicate that the modulation of rmf mRNA stability is also involved in the regulation of growth-phase-specific rmf expression. Unexpectedly, the postinoculation degradation of rmf mRNA was suppressed by the addition of rifampin, suggesting that de novo RNA synthesis is necessary for degradation. This degradation was also suppressed in both a poly(A) polymerase-deficient and an rne-131 mutant strain. We cloned and sequenced the 3′-proximal regions of rmf mRNAs and found that most of these 3′ ends terminated at the ρ-independent terminator with the addition of a one- to five-A oligo(A) tail in either stationary-phase or inoculated cells. No difference was observed in the length of the poly(A) tail between stationary-phase and inoculated cells. These results suggest that a certain postinoculation-specific regulatory factor participates in the destabilization of rmf mRNA and is dependent on polyadenylation.

scholarly journals Functional Sites of Ribosome Modulation Factor (RMF) Involved in the Formation of 100S Ribosome

2021 ◽  
Vol 8 ◽  
Author(s):  
Hideji Yoshida ◽  
Hideki Nakayama ◽  
Yasushi Maki ◽  
Masami Ueta ◽  
Chieko Wada ◽  
...  
Keyword(s):  
Amino Acids ◽  
Gradient Centrifugation ◽  
Essential Amino Acids ◽  
Sucrose Density Gradient ◽  
Bacterial Survival ◽  
Sucrose Density Gradient Centrifugation ◽  
Functional Sites ◽  
Ribosome Binding ◽  
Modulation Factor ◽  
Ribosome Modulation Factor

One of the important cellular events in all organisms is protein synthesis, which is catalyzed by ribosomes. The ribosomal activity is dependent on the environmental situation of the cell. Bacteria form 100S ribosomes, lacking translational activity, to survive under stress conditions such as nutrient starvation. The 100S ribosome is a dimer of two 70S ribosomes bridged through the 30S subunits. In some pathogens of gammaproteobacteria, such as Escherichia coli, Yersinia pestis, and Vibrio cholerae, the key factor for ribosomal dimerization is the small protein, ribosome modulation factor (RMF). When ribosomal dimerization by RMF is impaired, long-term bacterial survival is abolished. This shows that the interconversion system between active 70S ribosomes and inactive 100S ribosomes is an important survival strategy for bacteria. According to the results of several structural analyses, RMF does not directly connect two ribosomes, but binds to them and changes the conformation of their 30S subunits, thus promoting ribosomal dimerization. In this study, conserved RMF amino acids among 50 bacteria were selectively altered by mutagenesis to identify the residues involved in ribosome binding and dimerization. The activities of mutant RMF for ribosome binding and ribosome dimerization were measured using the sucrose density gradient centrifugation (SDGC) and western blotting methods. As a result, some essential amino acids of RMF for the ribosomal binding and dimerization were elucidated. Since the induction of RMF expression inhibits bacterial growth, the data on this protein could serve as information for the development of antibiotic or bacteriostatic agents.

The Ribosome Modulation Factor (RMF) Binding Site on the 100S Ribosome of Escherichia coli

2002 ◽  
Vol 132 (6) ◽  
pp. 983-989 ◽  
Author(s):  
H. Yoshida ◽  
Y. Maki ◽  
H. Kato ◽  
H. Fujisawa ◽  
K. Izutsu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Binding Site ◽  
Modulation Factor ◽  
Ribosome Modulation Factor

Involvement of ppGpp, Ribosome Modulation Factor, and Stationary Phase-Specific Sigma Factor ςS in the Decrease in Cell Viability Caused by Spermidine

1999 ◽  
Vol 264 (3) ◽  
pp. 643-647 ◽  
Author(s):  
Auayporn Apirakaramwong ◽  
Keiko Kashiwagi ◽  
V.Samuel Raj ◽  
Kaori Sakata ◽  
Yoshimi Kakinuma ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Cell Viability ◽  
Sigma Factor ◽  
Modulation Factor ◽  
Ribosome Modulation Factor

scholarly journals Novel gene members in the Pho regulon ofEscherichia coli

2006 ◽  
Vol 264 (1) ◽  
pp. 104-109 ◽  
Author(s):  
Jong Hwan Baek ◽  
Sang Yup Lee
Keyword(s):  
Ofescherichia Coli ◽  
Pho Regulon ◽  
Novel Gene
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