Biogenesis of mitochondria. Defective assembly of the proteolipid into the mitochondrial adenosine triphosphatase complex in an oli2 mit− mutant of Saccharomyces cerevisiae

A single mutation in the oli2 region of the mitochondrial DNA causes a charge alteration in a mitochondrially translated subunit of the mitochondrial ATPase (subunit 6; apparent M_r 20 000; apparent pI 6.9 and 7.1). This alteration leads to the defective assembly of the proteolipid subunit into the enzyme complex. The mutant, which is able to grow only very slowly by oxidative metabolism at 28°C offers new possibilities for studying the assembly of the membrane sector (F₀) into the mitochondrial ATPase complex and the role of subunit 6 in this process.     

Contribution to the study of cytokinin production by phytopathogenic fungi

The excretion of cytokinins into the cultivating medium, which are produced by the phytopathogenic fungiMonilia sp. andCytospora sp. has been investigated. All the isolates of the fungi used in the experiments (Monilia fructicola, Monilia fructigena, isolate 2 and 4,Monilia laxa isolate 3 andCytospora sp. isolate CPL and C₁) have been found to produce cytokinins. The production is increased during the formation of the fructification organs. Among the isolates investigatedMonilia fructigena isolate 4 andCytospora sp. isolate CPL showed the highest production of cytokinins. After chromatographic separation, cytokinin activity was found at R_F 0.7–0.8 values by the biological test as well as by identification according to UV spectra. Application of purified cytokinins produced by the fungi evoked the formation of “green islands” on isolated barley leaves underin vitro conditions.     

Primary sequence of the 16S ribosomal RNA of Escherichia coli.

Recent progress in the nucleotide sequence analysis of the 16S ribosomal RNA from E. coli is described. The sequence which has been partially or completely determined so far encompasses 1520 nucleotides, i.e. about 95% of the molecule. Possible features of the secondary structure are suggested on the basis of the nucleotide sequence and data on sequence heterogeneities, repetitions and the location of modified nucleotides are presented. In the accompanying paper, the use of the nucleotide sequence data in studies of the ribosomal protein binding sites is described.     

Evidence for tertiary structural RNA-RNA interactions within the protein S4 binding site at the 5''-end of 16S ribosomal RNA of Escherichia coli.+.

Evidence is presented for tertiary structural interaction(s) (interactions(s) between two regions of an RNA molecule that are widely separated in the RNA sequence) within the 5'-one third of the 16S ribosomal RNA of Escherichia coli that constitutes the binding site of protein S4. The two main interacting RNA regions were separated by about 120 nucleotides (sections Q to M) of the 16S RNA sequence. A second, smaller gap, of 13 nucleotides, occurred within section C". The two main interacting regions contain about 150 nucleotides (sections H" to Q) and 160 nucleotides (sections M to C"). They are folded back on one another and, especially in the presence of protein S4, are strongly protected against ribonuclease digestion. The intermediate region (sections Q to M), however, is relatively accessible to ribonucleases in the S4-RNP. By partial removal of subfragments from the RNA complex it was possible to localise the two main interacting sites within sections H" - H and sections I" - C". Three main criteria for the specificity of the RNA-RNA interactions were invoked and satisfied. The possibility of other tertiary structural RNA-RNA interactions occurring in other regions of the 16S RNA is discussed. Finally, all the structural information on the S4-RNP is summarised and a tentative model is proposed.     

Prefrontal deep projection neurons enable cognitive flexibility via persistent feedback monitoring

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Response to lethal UVA radiation in the Antarctic bacterium Pseudomonas extremaustralis: polyhydroxybutyrate and cold adaptation as protective factors

Extremophiles - Pseudomonas extremaustralis is an Antarctic bacterium with high stress resistance, able to grow under cold conditions. It is capable to produce polyhydroxyalkanoates (PHAs) mainly...     

Rosuvastatin protects isolated hearts against ischemia-reperfusion injury: role of Akt-GSK-3β, metabolic environment,and mitochondrial permeability transition pore

Journal of Physiology and Biochemistry - The cardioprotective activity of rosuvastatin (R) is yet to be known. The objective of this study was to research whether R perfusion before global ischemia...