"An error in model building"

Date:
1967
Reference:
PP/CRI/H/4/8
Catalogue details

Licence: In copyright

Credit: "An error in model building". Source: Wellcome Collection.

    1/55
    About a year ago Dr S.R. Pele and Miss M.G.E. WeIton claimed 1 that it is possible to fit amino-acids stereo chemical^ to their codons. They described how they built models using Courtauld space-filling components, but it'was not possible to tell from their very brief descriptions whether their models were stereochemical^ acceptable. I therefore corresponded with Dr Pele and he was kind enough to show me some of their models. Dr Pele produced several examples for me to examine but I will comment here only on their model of lysine fitted to AAG, as illustrated.in the photograph of Pig. 2 of the first of their two papers 1 . This model is stereochemical^ unacceptable for the following reasons: 1. The terminal - group of the lysine was built as - NH 2 . 2. In two places (one in the amino acid, one in the-triplet) adjacent methyl groups were in the eclipsed rather than the staggered configuration. 3. In two cases anj) NH, which should either make a satisfactory hydrogen bond, or at least be free to make one to a water molecule, was pointing directly