Tobacco mosaic virus assembled state

Any polymerization reaction in which the product of each elongation step can itself also undergo further polymerization. When the same types of bonds and/or conformational states that are present in the reactant(s) are generated within product(s) during elongation, the process is referred to as isodesmic polymerization. Such is the case for the indefinite polymerization of actin, tubulin, hemoglobin S, and tobacco mosaic virus coat protein. See Nudeation Protein Polymerization Actin Assembly Kinetics Microtubule Assembly Kinetics Microtubule Assembly Kinetics... 

Figure 12 Diagram of assembled states of the coat protein of tobacco mosaic virus M free monomers, BD cylindrical disks, LW/H protohelices and helices. Symbols results from differential scanning microscopy DSC, titration, and sedimentation experiments, lines theory. The theory is based on binding energy Equation (9) and presumes competing repulsive Coulomb and attractive hydrophobic interactions (Kegel and van der Schoot, 2006).

Many other examples of outwardly complex molecular structures, whose salient architectural features appear to self-assemble from their constituent building blocks, have been documented [16]. The formation of the DNA double helix from its constituent chains is perhaps the quintessential example, whilst the perfect reconstitution of the intact tobacco mosaic virus from its constituent RNA and protein monomers also exhibits all the hallmarks of a cooperative self-assembly process [17]. The same is true of ribonuclease. Reconstitution of this enzyme in the presence of mercaptoethanol, to allow reversible exchange of the four disulfide bridges, proceeds smoothly to generate eventually only the active conformation from many possible isomeric states [18], In each of these cases, the thermodynamic stability of the product is vital in directing its synthesis. These syntheses could therefore be termed product-directed. 

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