Protein synthesis by pure translation systems

Shimizu, Yoshihiro; Kanamori, Takashi; Ueda, Takuya

doi:10.1016/j.ymeth.2005.04.006

Cited by 342 publications

(302 citation statements)

References 17 publications

Supporting

Mentioning

301

Contrasting

Unclassified

Order By: Relevance

“…The PURE system used here and in some of the following experiments contains highly purified components, including RRF and EF-G (29,30); the latter reference contains a precise description of the components and their concentrations, except that our PURE system lacked IF1 and IF3, which we only added when indicated. Furthermore, we diminished the total Mg 2+ concentration from the usual 13-8.5 mM.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

70S-scanning initiation is a novel and frequent initiation mode of ribosomal translation in bacteria

Yamamoto

Wittek

Gupta

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

105

View full text Add to dashboard Cite

According to the standard model of bacterial translation initiation, the small ribosomal 30S subunit binds to the initiation site of an mRNA with the help of three initiation factors (IF1-IF3). Here, we describe a novel type of initiation termed "70S-scanning initiation," where the 70S ribosome does not necessarily dissociate after translation of a cistron, but rather scans to the initiation site of the downstream cistron. We detailed the mechanism of 70S-scanning initiation by designing unique monocistronic and polycistronic mRNAs harboring translation reporters, and by reconstituting systems to characterize each distinct mode of initiation. Results show that 70S scanning is triggered by fMet-tRNA and does not require energy; the Shine-Dalgarno sequence is an essential recognition element of the initiation site. IF1 and IF3 requirements for the various initiation modes were assessed by the formation of productive initiation complexes leading to synthesis of active proteins. IF3 is essential and IF1 is highly stimulating for the 70S-scanning mode. The task of IF1 appears to be the prevention of untimely interference by ternary aminoacyl (aa)-tRNA•elongation factor thermo unstable (EF-Tu)•GTP complexes. Evidence indicates that at least 50% of bacterial initiation events use the 70S-scanning mode, underscoring the relative importance of this translation initiation mechanism.protein synthesis | ribosomal functions | translational initiation | 30S-binding initiation | 70S-scanning initiation I t is textbook knowledge that 30S subunits initiate protein synthesis in bacteria; they recognize the initiation site of the mRNA composed of the Shine-Dalgarno (SD) sequence, the AUG codon, and fMet-tRNA, together with three initiation factors (IFs) forming the 30S initiation complex (30SIC). Association of the large 50S subunit triggers the release of the IFs, leading to the 70S initiation complex (70SIC) that enters the elongation phase of translation (reviewed in 1). We term this initiation path the "30S-binding mode" of bacterial initiation. After elongation and termination, it is thought that the ribosome dissociates into its subunits, thus providing 30S subunits for the next round of initiation.The functional role of IF2 is well defined. It can bind directly to the 30S, providing a docking site for fMet-tRNA (2), but it can also enter the 30S subunit as ternary complex fMet-tRNA•IF2•GTP (3). Both IF2 and IF3 are essential for viability. IF3 has a binding site at the 30S interface (4), which explains its antiassociation effect (5, 6), as well as its role in dissociation of the terminating 70S ribosome (7). However, the in vivo concentration of IF3 is 100-fold less (8) than required for full dissociation of 70S in vitro (4). Evidence for the presence of IF3 on 70S ribosomes was reported (9), indicating that the functional spectrum of IF3 is possibly not restricted to an antiassociation effect. Both IF3 and IF2 are also responsible for the fidelity of decoding the initiation AUG by fMet-tRNA Met f at the P site of 30S subun...

show abstract

Section: Resultsmentioning

confidence: 99%

“…), as well as the purified His-tagged IF1 and IF3. The expression in the PURE system was performed according to the method of Shimizu et al (30), with the following modifications. The final concentration of ribosomes in the reaction was 0.5 μM.…”

Section: Methodsmentioning

confidence: 99%

70S-scanning initiation is a novel and frequent initiation mode of ribosomal translation in bacteria

Yamamoto

Wittek

Gupta

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

105

View full text Add to dashboard Cite

show abstract

“…For example, chaperonins present in the extract are necessary for protein folding. Purified chaperonins have to be added to the PURE system to increase the amount of functional proteins produced (27). The endogenous proteases AAA þ present in E. coli extracts can be used for specific protein degradation (28).…”

Section: Bottom-up Development Of An Artificial Cell: Broad Consideramentioning

confidence: 99%

Development of an artificial cell, from self-organization to computation and self-reproduction

Noireaux¹,

Maeda

Libchaber

2011

Proc. Natl. Acad. Sci. U.S.A.

292

265

View full text Add to dashboard Cite

This article describes the state and the development of an artificial cell project. We discuss the experimental constraints to synthesize the most elementary cell-sized compartment that can self-reproduce using synthetic genetic information. The original idea was to program a phospholipid vesicle with DNA. Based on this idea, it was shown that in vitro gene expression could be carried out inside cell-sized synthetic vesicles. It was also shown that a couple of genes could be expressed for a few days inside the vesicles once the exchanges of nutrients with the outside environment were adequately introduced. The development of a cell-free transcription/translation toolbox allows the expression of a large number of genes with multiple transcription factors. As a result, the development of a synthetic DNA program is becoming one of the main hurdles. We discuss the various possibilities to enrich and to replicate this program. Defining a program for self-reproduction remains a difficult question as nongenetic processes, such as molecular self-organization, play an essential and complementary role. The synthesis of a stable compartment with an active interface, one of the critical bottlenecks in the synthesis of artificial cell, depends on the properties of phospholipid membranes. The problem of a self-replicating artificial cell is a long-lasting goal that might imply evolution experiments.Defining Life Since Schrödinger's classic book What Is Life? (1), the definition of life has always been a puzzle with a variety of partial answers, none really satisfying. One answer is that life is a coded system with mutation and error correction (2). The information is encoded into DNA (the genotype) and the genetic code allows translating this information into proteins (the phenotype). The genetic code is universal, and the genome can support mutations, recombination, duplication, and partial transfer from organisms to organisms. Error correction limits the risk of melting the information into random sequences. This is fine, but life is also metabolism with a permanent absorption and transformation of nutrients from the environment (3). A constant flux of energy is needed to sustain the operation of this living dynamical system out of equilibrium. But life is also self-reproduction (4). Cells originate from preexisting cells by cell division. The DNA genome is replicated, the cell self-reproduces as well as the complete organism. Is self-reproduction a constraint of evolution present at each step and imposing severe design constraints or a possible definition of life? Or is life an emerging phenomenon resulting from complex chemical reactions, developing networks and cycles until, at a certain critical size of this network, life starts as an emerging property (5)? Within this approach, life is a dynamical system where signal to noise is just marginal; a living system positions itself at the edge of chaos. Finally the only generally accepted theme is that life is the result of evolution, natural selection, and adaptation (6), a...

show abstract

“…3L-Pf3 coat was synthesized by means of PURE system, which was prepared as ACCEPTED MANUSCRIPT 6 described previously [9] except that magnesium acetate was reduced to 9 mM to avoid aggregation of liposomes. Liposomes were added at 400 g phospholipids/ml at the start of synthesis.…”

Section: In Vitro Synthesis and Integration Of 3l-pf3 Coatmentioning

confidence: 99%

A novel complete reconstitution system for membrane integration of the simplest membrane protein

Nishiyama

Maeda

Abe

et al. 2010

Biochemical and Biophysical Research Communications

Self Cite

View full text Add to dashboard Cite

A complete reconstitution system for membrane integration of the simplest protein was developed by means of defined factors. A mutant version of Pf3 coat protein, 3L-Pf3 coat, requires neither signal recognition particle/Sec factors nor a membrane potential for its integration into the cytoplasmic membrane of E. coli. Although 3L-Pf3 coat is spontaneously integrated into liposomes composed of phospholipids, diacylglycerol completely blocks such spontaneous integrations at a physiological level. Under the conditions where spontaneous integration does not occur, 3L-Pf3 coat integration was absolutely dependent on a novel integration-stimulating factor. Combination of the PURE system, an in vitro translation system composed of the purified factors involved in translation in E. coli, with liposomes containing the highly purified integration-stimulating factor revealed multiple cycles of 3L-Pf3 coat integration, achieving the complete reconstitution of membrane integration. Based on the function of the factor, we propose that the factor is named MPIase (Membrane Protein Integrase). Key wordsdiacylglycerol/integration-stimulating factor/liposomes/membrane protein integration/ MPIase/ PURE system ACCEPTED MANUSCRIPT 3

show abstract

Protein synthesis by pure translation systems

Cited by 342 publications

References 17 publications

70S-scanning initiation is a novel and frequent initiation mode of ribosomal translation in bacteria

70S-scanning initiation is a novel and frequent initiation mode of ribosomal translation in bacteria

Development of an artificial cell, from self-organization to computation and self-reproduction

A novel complete reconstitution system for membrane integration of the simplest membrane protein

Contact Info

Product

Resources

About