ribosome (redirected from P (peptidyl) site)

ribosome /ri·bo·some/ (ri´bo-som) any of the intracellular ribonucleoprotein particles concerned with protein synthesis; they consist of reversibly dissociable units and are found either bound to cell membranes or free in the cytoplasm. They may occur singly or occur in clusters (polyribosomes).riboso´mal

---

ri·bo·some (rb-sm)

n.

A minute round cytoplasmic particle composed of RNA and protein that is the site of protein synthesis as directed by mRNA.

---

ribo·somal (-sml) adj.

---

ribosome

ribonucleoprotein particles concerned with protein synthesis; they consist of two, one large and one small, reversibly dissociable units (called also 50S and 30S subunits) that are found either bound to cell membranes, particularly rough endoplasmic reticulum, or free in the cytoplasm. They may occur singly or in clusters, called polyribosomes or polysomes, which are ribosomes linked by mRNA and are actively engaged in protein synthesis.

---

ribosome binding site

a nucleotide sequence near the 5' terminus of mRNA required for binding of mRNA to the small ribosomal subunit. Called also Shine-Dalgarno sequence.