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A polyribosome (or polysome) is a complex of an mRNA molecule is translated by two or more ribosomes to form polypeptide chains during active translation, this process is called translatome.[1][5] Originally coined "ergosomes" in 1963 [2] they were further characterized by Jonathan Warner, Paul Knopf, and Alex Rich.[3] The study of translatome and polysome analysis would lead to a better insight of the complexity of the regulatory pathway; how mutations, extracellular stimuli, intercellular cues, growth conditions, and stress could lead to the change of translation in the cell, and which specific components would accompany to the translator machinery[5] [6] [7]. Ribosomes play a key role in the synthesis of polysome, they act as a platform for signaling molecules to get involved in the diverse modification from the emergence of polypeptides and ribosomes; also they aid the nascent polypeptides to fold with the presence of chaperones, later on would impact on the function of synthesized polysome[7].

Structure
Polysomes can be directly visualized by electron microsopy because they form very high molecular weight particles.[1] Many ribosomes simultaneously read one mRNA progressing along the mRNA to synthesize the same protein. They may appear as linear polysomes or circular rosettes with microscopy but are mainly circular in vivo. This circularization is aided by the fact that mRNA is able to be twisted into a circular formation, creating a cycle of rapid ribosome recycling and utilization of ribosomes. The 5' 7-methylguanosine cap and 3' poly(A) tail present on eukaryotic mRNA aid in this process.[4]

Types of Polysome
Polyribosomes can be found in three forms: free, cytoskeletal bound, and membrane bound. The three forms are detached by the difference of their poly(A) and non-poly(A) protein binding sequence from MPC-11 and Krebs II ascites cells using the procedure of detergent and salt extraction[8].