An effect of temperature on the Bacillus subtilis transfer RNA's which respond to codons beginning with U and a correlation with cytokinin activity

Abstract

1. 1. The fraction of unaminoacylated tRNA's from Bacillus subtilis that requires 1 M NaCl and 10% ethanol for elution from benzoylated DEAE-cellulose (BD-cellulose) contains amino acid acceptor activities for phenylalanine, serine, tyrosine, leucine, cysteine, and tryptophan. Codons beginning with U code for only the amino acids in this set. The amount of each of these tRNA species which binds to BD-cellulose is dependent on temperature. At 70°, more of these tRNA species require the addition of ethanol for elution. 2. 2. The chromatographic behavior of cytokinin activity is dependent on temperature in a similar manner. At room temeprature, some cytokinin activity is found in both 1 M NaCl eluted fractions and the fraction which requires 1 M NaCl and 10% ethanol for elution. At 70°, however, all cytokinin activity is retarded until ethanol is added to the eluant. 3. 3. The same effect caused by running the BD-cellulose column at 70° can be achieved by pretreating the tRNA's at 70° for 10 min and then running the column at room temperature. 4. 4. An explanation of this phenomenon is discussed in terms of molecular structure.