["The coding problem is essentially a theoretical problem..."]

Date:
[c. 1957]
Reference:
PP/CRI/H/2/24
Catalogue details

Licence: In copyright

Credit: ["The coding problem is essentially a theoretical problem..."]. Source: Wellcome Collection.

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    other chain, like this. But Brenner found that it was easily possible to make a code for twenty amino acids by choosing bases appropriately which never gave any of these sequences in the DNA. in DNA and both he and Burton find that the sequences aré -bertainly not random, and it is interesting that this result is just what you expect from codes of this general type, Now let us consider some of the difficulties about coding of a general nature. If the code were uniform throughout nature and and since the composition of proteins, by and large, does not vary so tremendously from one organism to another, we would certainly expect that the composition of DNA likewise would not show much variation. Unfortunately this is far from being the case. Por example, if one looks at the DNA from a number of species of bacteria as .... has done, one finds that the ratio of adenine : guanine can -] :be anywhere from about to about 2. Interestingly enough the composition of the RNA in these different species does not change very much. One can get round facts of this sort by assuming that there are stretches of in genetic material and that these may be of a rather simple base composition and may distort the final analysis, but one is not very happy with an argument of that kind. Then again it is surprising that DNA molecules can be fractionated into fractions which vary considerably in their base composition. In fact if it were not for the evidence I mentioned earlier, one would not infer from the analytical data that ^iucleic acid could cod© in a simple and uniform way for protein At this