What Is Protein Biosynthesis?

The process by which organisms synthesize proteins based on genetic information on messenger ribonucleic acid (mRNA) transcribed from DNA. Because the genetic information on mRNA is in the form of a code (see genetic code), only the synthesis of protein can express biological traits, so protein biosynthesis is compared to translation or translation. So RNA is a direct template for protein synthesis

Protein biosynthesis

Translation template

protein biosynthesis

Different mRNA sequences have different molecular sizes and base sequences, but all have 5-terminal untranslated regions, open reading frame regions, and 3-terminal untranslated regions; eukaryotic mRNAs also have caps on the 5-ends Structure, 3-ends with polyA nucleotides of varying lengths. The cap structure can be combined with the cap, participate in the localization and binding of mRNA on the ribosome during translation, and start protein biosynthesis; the cap structure and polyA tail are also stable

The ribosome is like a small mobile factory, which synthesizes peptide chains along the template of mRNA. Aminoacyl tRNA enters the ribosome at a great rate, transfers amino acids to the peptide chain, and is expelled from the ribosome from another position. The elongation factor also continuously binds and dissociates with the ribosome. Together, ribosomes and additional factors are

Regulation of protein biosynthesis

The rate of protein synthesis in the body is mainly at the level of transcription, and secondly it is regulated and controlled during translation. It is affected by a variety of factors such as gender, hormones, cell cycle, growth and development, health status and living environment, as well as changes in numerous biochemical substances involved in protein synthesis. Because translation and transcription of prokaryotes are usually coupled together and their mRNAs have a short life span, the speed of protein synthesis is mainly determined by the speed of transcription. Weakening is a way to regulate the speed of translation by first affecting the transcription through the excess and deficiency of translation products. The structure and properties of mRNA can also regulate the rate of protein synthesis.

HCR has active and inactive forms

Eukaryotic transcription and translation are not coupled, and protein synthesis is usually slower than prokaryotes. In addition to the regulation of eukaryotes mainly through transcription and post-transcriptional processing and the structure and properties of mRNA (such as cap structure and poly A tail) (see messenger ribonucleic acid), studies on globin biosynthesis have shown The start factor eIF-2 is the limiting factor for translation speed, so the factors affecting eIF-2 can regulate the translation speed. In vitro studies using mammalian reticulocyte-free preparations indicate that when hemoglobin is lacking, there is no need to synthesize proteins because hemoglobin cannot be formed. Experiments have shown that the regulation of heme is achieved through a type called heme-regulated repressor (HCR). HCR has active and inactive forms

Presence of red pigment inhibits cellular protein synthesis

Heme regulates proteins by affecting eIF-2. When heme is present, it inhibits cellular protein synthesis and also promotes the synthesis of proteins by cells that normally do not synthesize hemoglobin, such as the protein synthesis of cell-free preparations of liver cancer cells, Hella cells, and ascites tumor cells.

Inhibitors of protein biosynthesis

Inhibitors of protein biosynthesis Many inhibitors of protein biosynthesis are highly specific, which is important for studying the mechanism of synthesis. Many clinically effective antibiotics work by specifically inhibiting protein synthesis in prokaryotes. They inhibit bacterial growth without damaging human cells. Using the differences in the synthesis of two types of biological proteins, drugs can be found to treat diseases caused by bacterial infections. The table lists some of the more important inhibitors of protein biosynthesis, their sites of action, and specificity. ^[1]