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Figure 2–33 B. Quaternary structure of the hemoglobin molecule as determined by X-ray analyses (Based on Kendrew, 1961, 1963; Perutz, 1962, 1963; From Stent, 1974)
The problem of protein synthesis represents a “hot point” in biology
especially in its evolutionary aspect (see Chapter 1, Section 1. 6). Since
there are still no convincing data about self-replicating spiralized or non-spiralized
polypeptide chains this issue will be treated in the light of the
presently available conventional concepts.
According to modern views genetic information is encoded in the DNA
molecule. Under the action of the enzyme RNA-polymerase the process of
transcription of DNA is accomplished with the formation of messenger RNA
(mRNA). Transcription starts with RNA-polymerase joining a specific
nucleotide sequence in DNA called promotor. The double helix of DNA is
despiralized and at a definite portion of it a complementary RNA—DNA chain