Describe the information provided by:
Sequencing rRNA genes
The nucleotide sequence of ribosomal RNA (rRNA) can be used to identify prokaryotes, particularly those difficult or currently impossible to grow in culture. The prokaryote 70S ribosome, which plays an indispensable role in protein syntesis, is composed of protein and three different rRNAs (5S, 16S, and 23S). Because of their highly constrained and essential function, the nucleotide sequence changes that can occur in the rRNA's, ;yet still allow the ribosome to operate, are limited.