m[RNA]로 부터, [Protein]을 합성하는 세포질([Cytoplasm])내의 [Protein]-[RNA]복합체. One of the CellularComponent

0005840

An intracellular organelle, about 200 A in diameter, consisting of [RNA] and [Protein]. It is the site of [Protein] biosynthesis resulting from [Translation] of messenger [RNA] (mRNA).

It consists of two subunits, one large and one small, each containing only [Protein] and [RNA]. Both the ribosome and its subunits are characterized by their sedimentation coefficients, expressed in Svedberg units (symbol: S). Hence, the prokaryotic ribosome (70S) comprises a large (50S) subunit and a small (30S) subunit, while the eukaryotic ribosome (80S) comprises a large (60S) subunit and a small (40S) subunit. Two sites on the ribosomal large subunit are involved in [Translation], namely the aminoacyl site (A site) and peptidyl site (P site). Ribosomes from prokaryotes, eukaryotes, [Mitochondria], and [Chloroplast]s have characteristically distinct ribosomal proteins.

원핵세포 (70S [Ribosome])

• 50S : 5S r[RNA](120b) + 23S r[RNA](2904b) + 31 [Proteins]
• 30S : 16S r[RNA](1541b) + 21 [Proteins]

진핵세포 (80S [Ribosome])

• 60S : 5S r[RNA] + 5.8S r[RNA] + 28S r[RNA] + 50 [Proteins]
• 40S : 18S r[RNA] + 30 [Proteins]

보통 [Evolution]적 연관관계의 추적을 위해 16S, 18S r[RNA]서열이 활용된다.