Self-assembly biochemical

Processive catalysis of this kind involves extremely sophisticated molecular machinery including both RNA and protein components suggesting that it emerged relatively late in evolutionary terms. Processive catalysis is now a target for the design of artificial supramolecular machines and an interesting recent example is discussed in Section 10.7.3. 

The double-helical structure of DNA and the ability of the molecule to unravel in order to template the formation of copies of itself and transcribe RNA is clearly connected intimately with the supramolecular interactions that bind the two nucleotide strands together. It is the information encoded within the individual nucleobases that tells the molecule to form a double helix. This is an 

As an example of information encoding, consider the iron-storage protein ferritin. The protein comprises 24 identical subunits that, together, form a nearly spherical shell of octahedral symmetry. Why 24 subunits, and why octahedral symmetry Examination of the individual subunits 

Electron microscope image of the highly symmetrical icosahedral rotavirus (scale bar = 

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BIOCHEMICAL SELF-ASSEMBLY ACTIN ASSEMBLY KINETICS HEMOGLOBIN S POLYMERIZATION MICROTUBULE ASSEMBLY KINETICS BIOCONJUGATE BIOCONVERSION BIOLEACHING... 

ACTIN ASSEMBLY KINETICS BIOCHEMICAL SELF-ASSEMBLY FAD-dependent enzymes,... 

MICROSCOPIC DIFFUSION CONTROL MACROSCOPIC DIFFUSION CONTROL MICROSCOPIC REVERSIBILITY CHEMICAL REACTION DETAILED BALANCING, RRINCIRLE OF CHEMICAL KINETICS MICROTUBULE ASSEMBLY KINETICS BIOCHEMICAL SELF-ASSEMBLY ACTIN ASSEMBLY KINETICS HEMOGLOBINS POLYMERIZATION... 

ACTIN ASSEMBLY KINETICS BIOCHEMICAL SELF-ASSEMBLY BIOMINERALIZATION PRION PLAQUE FORMATION Nucleation as a highly cooperative process, MICROTUBULE ASSEMBLY KINETICS... 

Subunit assembly in multisubunit proteins, BIOCHEMICAL SELF-ASSEMBLY Subzero enzymology,... 

IRREVERSIBLE POLYMERIZATION Template-directed self-assembly, BIOCHEMICAL SELF-ASSEMBLY Template-independent irreversible polymerization,... 

Biochemical self-assembly proceeds by fundamental supramolecular principles and can lead to structures of startling complexity including DNA and viral capsids. 

We have already dealt with some general aspects of biochemical self-assembly in Section 2.10 including the remarkable formation of viral capsids. There are some biochemical examples, however, that translate readily into supramolecular chemical concepts and have been pivotal in defining the field. One such system is the tobacco mosaic virus, a virus that is very harmful to a variety of crops including tobacco, tomato, pepper, cucumbers and species such as ornamental flowers. This system consists of a helical virus particle measuring some 300 X 18 nm (Figure 10.6). A central strand of RNA is sheathed by 2130 identical protein subunits, each of which contains 158 amino acids. What is remarkable about... 

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