CHAIN TERMINATION CODONS AND POLYMERASE-INDUCED FRAMESHIFT MUTATIONS

The consensus sequence for single-base deletions in non-reiterated run s during in vitro DNA-dependent DNA polymerisation is refined using da ta available in the literature. This leads to the observation that cha in termination codons are hotspots for single-base deletions. The evol utionary implications are discussed in two models which differ in whet her polymerases evolved while the genetic code emerged or after the ge netic code was fixed. A possible answer to the question 'Why are stop codons just what they are?' is suggested. (C) 1997 Federation of Europ ean Biochemical Societies.