Novel insights into the architecture and protein interaction network of yeast eIF3.

Translation initiation in eukaryotes is a multistep process requiring the orchestrated interaction of several eukaryotic initiation factors (eIFs). The largest of these factors, eIF3, forms the scaffold for other initiation factors, promoting their binding to the 40S ribosomal subunit. Biochemical and structural studies on eIF3 need highly pure eIF3. However, natively purified eIF3 comprise complexes containing other proteins such as eIF5. Therefore we have established in vitro reconstitution protocols for Saccharomyces cerevisiae eIF3 using its five recombinantly expressed and purified subunits. This reconstituted eIF3 complex (eIF3(rec)) exhibits the same size and activity as the natively purified eIF3 (eIF3(nat)). The homogeneity and stoichiometry of eIF3(rec) and eIF3(nat) were confirmed by analytical size exclusion chromatography, mass spectrometry, and multi-angle light scattering, demonstrating the presence of one copy of each subunit in the eIF3 complex. The reconstituted and native eIF3 complexes were compared by single-particle electron microscopy showing a high degree of structural conservation. The interaction network between eIF3 proteins was studied by means of limited proteolysis, analytical size exclusion chromatography, in vitro binding assays, and isothermal titration calorimetry, unveiling distinct protein domains and subcomplexes that are critical for the integrity of the protein network in yeast eIF3. Taken together, the data presented here provide a novel procedure to obtain highly pure yeast eIF3, suitable for biochemical and structural analysis, in addition to a detailed picture of the network of protein interactions within this complex

The effects of inductive teaching system on design results of architectural design4 (Case study: Khayyam University of Mashhad)

Background and Objectives: The main aim of architectural schools is to train professional architectures who can design and organize the living spaces for people. But unfortunately these days most of them have not reach this goal. The most important reason of this issue is that the topics in the architectural schools do not correspond with the needs of professional workplaces. So it is important for the architectural schools to train professional architects who have enough abilities to start working, design and build real places.The 5 courses of architectural design studio are very important in learning system of Iranian architectural Universities. So it is important to analyse different teaching methods and their effects on each of these courses. In the first part of this article, the course programs of architectural design 4 have been analysed. The topics, goals and the steps of each method is explained; and in the following the effect of inductive teaching method has been analysed at Khayyam University of Mashhad as the case study of the research. The hypotheses of the research explore that the inductive teaching method let the students design more creative and rational projects, fulfil the needs of the projects that have correct relations among the spaces. Methods: The case study is Khayam university of Mashhad because one of the researchers of this research has been teaching in this university for many years. The research method is descriptive and analytical and survey research; and information was gathered by a questionnaire, observation and documental studies.The validity of questionnaire is controlled by content validity method and the reliability of the information was controlled by triangular method. The gathered information were analysed with content analysis, Spss software, graphical and deductive analysis. Findings: The results show that inductive teaching system let the students design more rational projects, which fulfil the needs of the projects that have correct relations among the spaces. These projects will be more executive and reach the architectural training goals in the school’s topics, define a better relation between the standards of the project and creative concepts and ideas and finally these projects will have better space quality that correspond with the topic of the design. But this method of teaching design process restricts the student’s creativity. Conclusion: changing the teaching methods architectural schools, changes the design process and the results of the final projects. There is a meaningful relationship between the independent and dependent variable. Because the correlation coefficient between the method of teaching designing process and the final result is good. According to the results of field studies and the research’s background we can claim that there is a relation between the teaching method of design process and the results. Each of the teaching method, according to their goals and topics which they focus on, can be successful in designing a good architectural project that fits the needs and functional conditions    In future researchways to alleviate the problems ofthis instructional approach that led to limiting students’ creativity are recommended.   ===================================================================================== COPYRIGHTS  ©2020 The author(s). This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, as long as the original authors and source are cited. No permission is required from the authors or the publishers.  ====================================================================================

Crystal Structure of the RNA Recognition Motif of Yeast Translation Initiation Factor eIF3b Reveals Differences to Human eIF3b

BACKGROUND: The multi-subunit eukaryotic initiation factor3 (eIF3) plays a central role in the initiation step of protein synthesis in eukaryotes. One of its large subunits, eIF3b, serves as a scaffold within eIF3 as it interacts with several other subunits. It harbors an RNA Recognition Motif (RRM), which is shown to be a non-canonical RRM in human as it is not capable to interact with oligonucleotides, but rather interacts with eIF3j, a sub-stoichiometric subunit of eIF3. PRINCIPAL FINDING: We have analyzed the high-resolution crystal structure of the eIF3b RRM domain from yeast. It exhibits the same fold as its human ortholog, with similar charge distribution on the surface interacting with the eIF3j in human. Thermodynamic analysis of the interaction between yeast eIF3b-RRM and eIF3j revealed the same range of enthalpy change and dissociation constant as for the human proteins, providing another line of evidence for the same mode of interaction between eIF3b and eIF3j in both organisms. However, analysis of the surface charge distribution of the putative RNA-binding β-sheet suggested that in contrast to its human ortholog, it potentially could bind oligonucleotides. Three-dimensional positioning of the so called "RNP1" motif in this domain is similar to other canonical RRMs, suggesting that this domain might indeed be a canonical RRM, conferring oligonucleotide binding capability to eIF3 in yeast. Interaction studies with yeast total RNA extract confirmed the proposed RNA binding activity of yeast eIF3b-RRM. CONCLUSION: We showed that yeast eIF3b-RRM interacts with eIF3j in a manner similar to its human ortholog. However, it shows similarities in the oligonucleotide binding surface to canonical RRMs and interacts with yeast total RNA. The proposed RNA binding activity of eIF3b-RRM may help eIF3 to either bind to the ribosome or recruit the mRNA to the 43S pre-initiation complex

From Architectured Materials to Large-Scale Additive Manufacturing

The classical material-by-design approach has been extensively perfected by materials scientists, while engineers have been optimising structures geometrically for centuries. The purpose of architectured materials is to build bridges across themicroscale ofmaterials and themacroscale of engineering structures, to put some geometry in the microstructure. This is a paradigm shift. Materials cannot be considered monolithic anymore. Any set of materials functions, even antagonistic ones, can be envisaged in the future. In this paper, we intend to demonstrate the pertinence of computation for developing architectured materials, and the not-so-incidental outcome which led us to developing large-scale additive manufacturing for architectural applications

Developments in construction-scale additive manufacturing processes

Additive manufacturing in construction is beginning to move from an architect's modelling tool to delivering full-scale architectural components and elements of buildings such as walls and facades. This paper discusses large-scale additive manufacturing processes that have been applied in the construction and architecture arena and focuses on ‘Concrete Printing’, an automated extrusion based process. The wet properties of the material are critical to the success of manufacture and a number of new criteria have been developed to classify these process specific parameters. These criteria are introduced and key challenges that face construction scale additive manufacturing are presented