PubMed Health⌕ Search

Biomedical subjects

S K Zavriev

Publications and source records attributed to S K Zavriev.

44 records · Page 3Linked to original sources
PubMedDate not supplied

[Kinetic determination of the non-specific constants for the binding of Escherichia coli RNA polymerase to T7 phage DNA].

The kinetics of promoter complex formation of E. coli RNA polymerase with T7 phage DNA was studied under different ionic strengths at DNA concentrations 0.15, 1.5 and 20 microns/ml. Based on the results obtained the non-specific binding constants, Keq, and the promoter complex formation rate constants, kp, were estimated. Within ionic strength range 0 + 125 mM NaCl the Keq and kp vary from 5.10(6) to 9.10(5) M-1 and from 0.8 x 0.26 x 10(9) M-1 S-1, respectively. The results are discussed from the view point of the one-dimensional diffusion sliding of the enzyme along DNA in the process of phomoter site selection.

DNA, Viral↗
PubMedDate not supplied

[Discontinuous transfer of phage T7 DNA molecules into Escherichia coli cells during infection].

HpaI restriction analysis of the part of T7 DNA molecule which comes off from E. coli after ultrasonic desorption of virion had been carried out. In such a way it was possible to follow the transfer of labelled T7 DNA into the host cell after the phage adsorption under different conditions. It was established that in the presence of chloramphenicol the left 60% of T7 chromosome is gradually (during 20 min) transferred into the cell and further transport is stopped. This suggests that some T7 gene(s) of I or (and) II class(es) is (are) necessary to transfer the last 40% of T7 DNA molecule containing the genes encoding capsid proteins. Also some new results are obtained which support thr idea about the tight coupling of the processes of T7 DNA transport and its transcription, and about the possibility for RNA polymerase to carry a mechanical function as well. All these results suggest a rather complicated mechanism of the process of T7 DNA transfer into the host cell consisting of at least three stages tightly connected with T7 gene expression temporal control. Some probable consequences of this model as well as its agreement with functional structure of T7 chromosome and with T7 development are discussed.

Chloramphenicol↗
PubMedDate not supplied

[42K protein of shallot X virus is expressed in infected Allium species plants].

The main difference between genome structures of shallot virus X (ShVX) and related potex- and carlaviruses is the unique gene of ShVX coding for a 42K protein. The amino acid sequence of this protein was analyzed and compared with those of similar proteins from several newly characterised viruses of garlic. Using antibodies against the recombinant 42K protein, expression of the 42K protein of ShVX was detected in most of plants where the ShVX coat protein is present.

Allium↗