  Present day data allow significant reconsideration of ideas on mechanisms
underlying the degeneracy in the genetic code. Here a hypothesis is presented
which links the degeneracy to possible conformational alterations in the
codon-anticodon duplex. This enables explanation of Rumer symmetry in the table
of the genetic code, coding of methionine and tryptophane without degeneracy
and predict significant difference between thymine and uracyl. The suggested
hypothesis has something in common with Lagerkvist idea that only two
nucleotides in codon are coding.
