Ribosomes， the organelles which catalyze protein synthesis， contain a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and nearly 80 structurally distinct proteins. This gene encodes a ribosomal phosphoprotein which is a component of the 60S subunit. The protein， which is a functional equivalent of the E. coli L7/L12 ribosomal protein， is a member of the L12P family of ribosomal proteins and has a vital part in the elongation step of protein synthesis. In opposed to most ribosomal proteins， which are basic， the encoded protein is acidic.The P1 C-terminal end is nearly identical to the C-terminal ends of the ribosomal phosphoproteins P0 and P2. The P1 protein can interact with P0 and P2 to form a pentameric complex consisting of P1 and P2 dimers， and a P0 monomer. P1 is located in the cytoplasm. Two alternatively spliced transcript variants which encode varies proteins have been detected. As is typical for genes encoding ribosomal proteins， there are multiple processed pseudogenes of this gene distributed all over the genome.
