1分子生物学第九章 蛋白质合成

Transcription generates an RNA which is complementary to the DNA template strand and has the same sequence as the DNA coding strand. Translation reads each triplet of bases into one amino acid. Three turns of the DNA double helix contain 30 bp, which cide for 10 amino acids.
Aminoacyl-tRNA synthetases are enzymes responsible for covalently linking amino acids to the 2′- or 3′-OH position of tRNA.
Anticodon反密码子 is a trinucleotide三核苷酸sequence in tRNA which is complementary to the codon in mRNA and enables the tRNA to place the appropriate amino acid in response to the codon.
Hale Waihona Puke Baidu
The tRNA cloverleaf 三叶草结构 has invariant不变的 and semi-invariant bases, and a conserved 保守 的set of base pairing
interactions.
Transfer RNA folds into a compact L-shaped tertiary structure 三级结 构with the amino acid at
Transfer RNA is the adapter
Aminoacyl氨酰-tRNA is transfer RNA carrying an amino acid; the covalent 共价linkage is between the NH2 group of the amino acid and either the 3′- or 2′-OH group of the terminal base of the tRNA.
A polyribosome多核糖体consists of an mRNA being translated simultaneously by several ribosomes moving in the direction from 5' -3' . Each ribosome has two tRNA molecules, one carrying the nascent amino acid初生氨基酸, the second carrying the next amino acid to be added 添加氨基酸.
Stem is the base-paired segment of a hairpin.
A tRNA has the dual properties of an adaptor that recognizes both the amino acid and codon. The adenosine腺苷at 3' end is covalently linked to an amino acid. The anticodon base pairs with the codon on mRNA.
Loop 环is a single-stranded region of a hairpin发夹 in RNA (or singlestranded DNA); corresponds to the sequence between inverted repeats 反向重复in duplex DNA.
The meaning of tRNA is determined by its anticodon and not by its amino acid.
Messenger RNA is translated by ribosomes 核糖体
A ribosome consists of two subunits亚基.
Chapter 9
Protein synthesis
Introduction
Coding region编码区 is a part of the gene that represents a protein sequence. Coding strand 编码链of DNA has the same sequence as mRNA. template strand模板链 of double-stranded DNA is the one that is used to specify the sequence of a complementary single strand of RNA. (The non-template strand is identical in sequence to the RNA product.) Transcription 转录is synthesis of RNA on a DNA template. Translation 翻译is synthesis of protein on the mRNA template.
one end and the anticodon at the other end.
A space-filling model shows that tRNA tertiary structure is compact 紧密的. The two views of tRNA are rotated by 90 o. Photograph kindly provided by S. H. Kim.