A structure has been obtained for the loop E region of the 5S rRNA from Spinacia oleracia chloroplast ribosomes using residual dipolar coupling data as well as NOE, J coupling and chemical shift information. Even though the loop E sequence of this chloroplast 5S rRNA differs from that of Escherichia coli loop E at approximately 40% of its positions, its conformation is remarkably similar to tha...

A lipid requirement for photosystem I activity in Spinacia oleracea chloroplasts has been characterized. The transfer of electrons from tetramethyl-p-phenylenediamine through the chloroplast photosystem to viologen dye was used as an assay of photosystem I activity. Activity is diminished by prolonged heptane extraction and is partially restored by readdition of the extracted lipid. Extracted c...

Steady-state and pre-steady-state kinetics for the hydrolysis of p-nitrophenyl esters of N-alpha-carbobenzoxy(-l-)amino acids catalyzed by leucine-proteinase were determined between pH 5 and 10 (I = 0.1 molar) at 23 +/- 0.5 degrees C. For the substrates considered: (a) the acylation step is rate-limiting in catalysis; (b) the pH profiles of k(cat) and k(cat)/K(m) reflect the ionization of two g...

The Cladosporium herbarum complex comprises five species for which Davidiella teleomorphs are known. Cladosporium herbarum s. str. (D. tassiana), C. macrocarpum (D. macrocarpa) and C. bruhnei (D. allicina) are distinguishable by having conidia of different width, and by teleomorph characters. Davidiella variabile is introduced as teleomorph of C. variabile, a homothallic species occurring on Sp...

5S rRNAs from Spinacea oleracea cytoplasmic and chloroplastic ribosomes have been subjected to digestion with the single strand specific nuclease S1 and to chemical modification of cytidines by sodium bisulphite in order to probe the RNA structure. According to these data, cytoplasmic 5S rRNA can be folded as proposed in the general eukaryotic 5S rRNA structure (1) and 5S rRNA from chloroplasti...

Increased photosynthetic CO(2) assimilation by Chlamydomonas reinhardtii cells treated with triacontanol (TRIA) was not due to changes in glycolate excretion, CO(2) compensation point, or the sensitivity of photosynthetic CO(2) assimilation to O(2). Kinetic analysis of TRIA-treated cells showed that the increase in photosynthetic CO(2) assimilation was a result of an increase in the apparent V(...