rplB

rplB is a gene that encodes the 50S ribosomal subunit protein L2 in bacteria. L2 is a core component of the large ribosomal subunit and is essential for protein synthesis. It contributes to the structure of the peptidyl transferase center, binds to 23S rRNA, and stabilizes the ribosome during translation. L2 is among the most conserved ribosomal proteins, with wide distribution across bacteria and homologs in other domains of life.

The rplB gene is typically about 250–320 amino acids in length, with a basic, RNA-binding character. In many bacteria, rplB is a single-copy gene located within operons encoding other ribosomal proteins. Because of its conservation and single-copy status, rplB is used in phylogenetic analyses and as a marker in comparative genomics, sometimes complementing or providing alternatives to 16S rRNA.

Disruptions or mutations in rplB can affect ribosome function and bacterial fitness, reflecting its essential role in ribosome assembly and translation. The encoded protein is typically around 25–30 kDa. As a highly conserved, essential ribosomal component, rplB serves as a useful reference point in evolutionary studies and a baseline in investigations of ribosome biology.