Ribosomal ribonucleic acid synthesis in Bacillus subtilis

Area of Science:

• Microbiology
• Molecular Biology
• Biochemistry

Background:

• Ribosomal ribonucleic acids (rRNA) are essential components of ribosomes, crucial for protein synthesis.
• Understanding rRNA biosynthesis provides insights into bacterial gene expression and cellular function.

Purpose of the Study:

• To investigate the mode of biosynthesis for 16S and 23S rRNA in Bacillus subtilis.
• To characterize the synthesis rates and chain lengths of these rRNA molecules.

Main Methods:

• Analysis of de novo rRNA synthesis rates at 37°C in growing cultures.
• Assessment of 3'-terminal group reactivity using periodate and [carbonyl-(14)C]isonicotinic acid hydrazide.
• Evaluation of 5'-terminal region reactivity with a bacterial exonuclease.

Main Results:

• 16S and 23S rRNA chains were synthesized at comparable rates (22±2 and 21±2 nucleotides/s, respectively).
• The 23S rRNA chain length was approximately 1.8 times that of the 16S rRNA.
• Apparent chain lengths were determined as 1650±50 residues for 16S rRNA and 3050±90 residues for 23S rRNA.

Conclusions:

• Bacillus subtilis 16S and 23S rRNA molecules are synthesized via simple polymerization.
• The biosynthesis follows the expected pattern, with independent cistrons producing the final rRNA products.