Location of gene specifying cytosine deaminase in Escherichia coli

Summary The gene specifying cytosine deaminase (cod) is shown to be located at approximately 86 minutes on the linkage map of E. coli. The corresponding gene in S. typhimurium has been reported to have a different location.     

Evaluation of the professional qualities of operators working with computer displays

The influence of spatio-temporal factors (spatial heterogeneity of distribution of the numbers sought for in the matrix of data, processes of learning and development of fatigue, periodic attention oscillations) of the character of solving the task of searching the numbers in a matrix of 176 three-figure numbers (16 lines, 11 columns) was studied in 39 operators. The possibility was shown to use the characteristics obtained for evaluation of professionally important abilities of an operator working at the display.     

Genetic determination of the vibriocinogenicity trait in Vibrio cholerae of the El Tor biotype

In two different strains of cholera vibrios two recA-dependent plasmids, pVib I (1.9-2.2 Md) and pVib II (5.2-5.8 Md), have been detected. These plasmids determine the synthesis of vibriocin, coagulase and fibrinolysin, which has been established by the cotransformation of the DNA of plasmids pVib I and pBR322 and by the transfer mobilization with the use of plasmid RP4.     

Pseudomonas aeruginosa cytochrome oxidase. Product inhibition by low thermodynamic driving force

The steady-state kinetics of Pseudomonas aeruginosa cytochrome oxidase were studied. Reduced cytochrome c551 and azurin from the same bacteria were used as the electron-donating substrates, while dioxygen served as the electron acceptor. Oxidized cytochrome c551 and azurin exhibited product inhibition of the reaction. However, apo-azurin and azurin derivatives in which the copper was substituted by the redox-inert ions Ni2+, Co2+, Cd2+ and Zn2+, did not show any effect on the kinetics. These observations implied that complex formation between the substrates or the products and the enzyme is not a rate-limiting step and is not the cause for product inhibition. The integrated rate law for a reaction scheme in which we assumed that complex formation was not rate limiting was fitted to the complete reaction traces. The results suggested that it is the low thermodynamic driving force, expressed in the small differences in redox potential between the substrates and heme c of the enzyme, which cause the observed product inhibition.