ABSTRACT
As it was shown in studies of J. Dubochet using the recently developed method of three-dimensional cryo-microscopy, the interaction of RNA polymerase with plasmid gives rise to a superhelical structure. In this process, two RNA polymerase molecules are located at opposite ends of the plasmid at the tops of the superhelix. The dynamic features of this process are considered, which may be only one of many similar processes, in which energy dissipation during the directed movement of DNA is reduced to a minimum. It is assumed that, upon screwing of two double helices into each other, a three- dimensional mechanical transmission is formed, owing to the spatial features of the double helices comprising the superhelix, which further facilitates this twisting process.
Subject(s)
DNA, Recombinant/chemistry , DNA, Superhelical/chemistry , DNA-Directed RNA Polymerases/chemistry , Nucleic Acid Conformation , PlasmidsABSTRACT
In [1], the existence of two competing secondary structures at the 5'-end of Leptomonas collosoma spliced leader RNA was shown. On going from one steady-state secondary structure to the other, and vice versa, RNA passes through several states in which the chain gets tied up into nodes. If the transitions are reversible, the nodes are figurative both in the forth and back directions although the secondary structures that arise in this process are quite different, and the forth and back routs do not coincide. It is assumed that under certain conditions, the chain can get tied into the next node of series 5(2), which most likely will not get untied. This node is tightened around GG nucleotides. In this case, the migration of the gap is possible, as a result of which the chain can break. Independent experiments indicate that the RNA chain breaks just at this site upon splicing. Based on these results, a possible role of nodes in the enzymatic activity is discussed.
Subject(s)
RNA Splicing , RNA, Messenger/chemistry , RNA, Protozoan/genetics , Trypanosomatina/genetics , Animals , Base Sequence , Molecular Sequence Data , Nucleic Acid Conformation , RNA, Messenger/genetics , RNA, Protozoan/chemistryABSTRACT
In the present contribution the algebra of color vision has been developed. This algebra is similar to that of spinors. In this formalism, white color corresponds to zero, and any color on color circle goes to complex number. So the color intensity corresponds to the modulus of complex number, as the color itself is the phase of complex number. The schemes of Young-Helmholtz and Hering have been considered. It is demonstrated that these schemes both generate the same algebra of complex numbers, though projective-geometrical algorithm are different.
Subject(s)
Color Perception/physiology , Algorithms , Models, TheoreticalABSTRACT
The sequence of nucleotides in a single-stranded RNA molecule is represented by a complex vector, whose k-th component corresponds to the k-th base of the sequence ordered in the 5'3' direction. An analysis of the proposed formalisms permits to predict a new type of reversible conformational transitions between the secondary structure patterns of RNA which may have an oscillatory character. A possible experimental approach based on the ESR technique for recording and time-scale estimation of these transitions is proposed.
Subject(s)
Genetic Vectors , RNA/chemistry , Electron Spin Resonance Spectroscopy , Nucleic Acid ConformationABSTRACT
With the help of retarded double-time Green function technique a method of estimation of electron transfer rate in protein macromolecules has been developed. Possible experimental test is suggested.
Subject(s)
Electron Transport , Peptides/chemistry , Kinetics , MathematicsABSTRACT
It was demonstrated that the relations between substrate and product concentrations for a reaction catalyzed by michaelian enzyme incorporated in a multienzyme system can be graphically represented by a diverging set of straight lines intersecting in one point, the flux velocity being treated as a parameter. A competitive inhibitor shifts the intersection point along the line of equilibrium state. The relations between the concentrations of more than two reagents are represented by a set of equivelocity surfaces. The relations between substrate and product concentrations for a kinetically cooperative reaction conforming to the graphical representation by the second--order curves were analyzed. The stability criterion was obtained for a multienzyme system with the first enzyme allosterically regulated by products of subsequent reactions.
Subject(s)
Enzymes , Allosteric Regulation , Binding, Competitive , Catalysis , Enzyme Inhibitors , Kinetics , Models, ChemicalABSTRACT
Methods based on the graphical representation of relations between metabolites concentrations were worked out for the description and analysis of the steady-state kinetics of the multienzyme systems. The properties of graphics characterizing various steady-state regimens were investigated. Relations relevant to the analysis of regulatory phenomena were derived for the concentration of non-adjacent metabolites. Rules are presented for the kinetical description of multienzyme systems posessing external inputs and outputs. Certain branchings occuring in multienzyme systems were considered. The developed methods allow generalization concerning multisubstrate multiproduct reactions as well as systems containing regulatory enzymes with non-michaelian kinetics. It is suggested that the generalized methods may be helpful for the analysis of the metabolic regulation.
Subject(s)
Enzymes/metabolism , Catalysis , Kinetics , Mathematics , Models, ChemicalSubject(s)
Kinetics , Acid Phosphatase , Hot Temperature , Mathematics , Methods , Protein DenaturationABSTRACT
A new graphic method is proposed to solve kinetic equations for polyenzymic reactions. Each graph apex is corresponded by the transmitting function deduced from kinetic equations by means of Laplas transformation. Application of this procedure allows to simplify the solution of kinetic equations and its analysis. The procedure suggested makes it possible to use the methods of automatic control when solving theoretical problems of enzymology.