\u3cem\u3ePlasmodium falciparum\u3c/em\u3e SSB Tetramer Wraps Single-Stranded DNA with Similar Topology but Opposite Polarity to \u3cem\u3eE. coli\u3c/em\u3e SSB

Single-stranded DNA binding (SSB) proteins play central roles in genome maintenance in all organisms. Plasmodium falciparum, the causative agent of malaria, encodes an SSB protein that localizes to the apicoplast and likely functions in the replication and maintenance of its genome. P. falciparum SSB (Pf-SSB) shares a high degree of sequence homology with bacterial SSB proteins but differs in the composition of its C-terminus, which interacts with more than a dozen other proteins in Escherichia coli SSB (Ec-SSB). Using sedimentation methods, we show that Pf-SSB forms a stable homo-tetramer alone and when bound to single-stranded DNA (ssDNA). We also present a crystal structure at 2.1 Å resolution of the Pf-SSB tetramer bound to two (dT)35 molecules. The Pf-SSB tetramer is structurally similar to the Ec-SSB tetramer, and ssDNA wraps completely around the tetramer with a “baseball seam” topology that is similar to Ec-SSB in its “65 binding mode”. However, the polarity of the ssDNA wrapping around Pf-SSB is opposite to that observed for Ec-SSB. The interactions between the bases in the DNA and the amino acid side chains also differ from those observed in the Ec-SSB–DNA structure, suggesting that other differences may exist in the DNA binding properties of these structurally similar proteins

Data Protection and Packet Mode in the Distributed Information Measurement and Control System for Research in Physics

The present paper is devoted to creation of cryptographic data security and realization of the packet mode in the distributed information measurement and control system that implements methods of optical spectroscopy for plasma physics research and atomic collisions. This system gives a remote access to information and instrument resources within the Intranet/Internet networks. The system provides remote access to information and hardware resources for the natural sciences within the Intranet/Internet networks. The access to physical equipment is realized through the standard interface servers (PXI, CАМАC, and GPIB), the server providing access to Ethernet devices, and the communication server, which integrates the equipment servers into a uniform information system. The system is used to make research task in optical spectroscopy, as well as to support the process of education at the Department of Physics and Engineering of Petrozavodsk State University

Retrovirus Integrase-DNA Structure Elucidates Concerted Integration Mechanisms

Commentary on Hare, S.; Gupta, S.S.; Valkov, E.; Engelman, A.; Cherepanov, P. Retroviral intasome assembly and inhibition of DNA strand transfer. Nature 2010, 464, 232–236

Russian Professor as a Laborer in the Era of Ratings, Digitalization and the COVID-19 Pandemic

The traditional labor contract has actually ceased to be the principal legal document, regulating labor relations of Russian university teachers. The individual labor contract was reduced to the status of a mere ‘rudimentary’ annex to the so-called effective contract. The latter is legally non-existent and is not even mentioned in the Labor Code of Russia of 2001. The Covid-19 pandemic with its isolationist features aggravated the absurd paradigm change within the Russian Labor law. As a result, the illegitimate effective contract has virtually supplanted the regular labor contract. There may be traced three dominant features of the new labor regime, induced by the Covid-19 pandemic. Firstly, the said labor regime fosters social dissociation of former (ante-pandemic) colleagues with the inevitable harm to the social nature and human dignity of homo faber. Secondly, we can witness the strengthening of the external  - via internet -  exploitation of university teachers by a corresponding managerial staff and the merging of this exploitation with the academic staff’s self-exploitation. Thirdly, the said regime is responsible for virtual disappearance of difference between working days of university teachers and leisure hours, previously reserved for reading and research

French books with Catherine II´s coat of arms from the former Hermitage Library

Among the books transferred from the Hermitage library to the Imperial Public Library (now National Library of Russia, NLR) in the middle of the 19th century, special attention should be given to the books having the imperial coat of arms of the Catherine II’s epoch on the covers. These copies should be studied in the context of the attention which was given by the French scientific community to the Russian Empress at this time. It is necessary to note that authors (or editors of these works)..

Modelling of the process of vibro-mechanical correction in long-length parts

The article describes a vibro-mechanical method of residual stress relaxation in long-length parts of the “shaft” type. The method is based on creation and uniform motion of plasto-elastic deformation zone generated by the bending moment at continuous rotation of the part. This leads to occurrence of the high-cyclic loading. Under controlled high-cyclic loading there occur accumulation and subsequent relaxation of residual stresses. The process of vibro-mechanical residual stress relaxation is described by a mathematical model which establishes relation between the geometrical, physical-mechanical and process-dependent parameters. The mathematical model is based on the energy approach to the description of plasto-elastic deformation of a part at high-cyclic loading. The results of experiments with the application of the presented model are given in graph form. They describe the dependence of the residual stress values on the duration of vibro-mechanical processing

Microwave and Millimeter Wave Technologies A New X-Band Mobile Direction Finder

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