Context sequences of translation initiation codon in plants.

In this survey of 5074 plant genes for their AUG context sequences, purines are present at the -3 and +4 positions in about 80% of the sequences. Although this observation is similar to the vertebrate consensus sequence, the number of plant mRNAs with purines at the -3 position is lower and at the +4 position is higher than reported for vertebrate mRNAs. Higher plants have an AC-rich consensus sequence. caA(A/C)aAUGGCg as a context of translation initiator codon. Between the two major groups of angiosperms, the context of the AUG codon in dicot mRNAs is aaA(A/C)aAUGGCu which is similar to the higher-plant consensus but monocot mRNAs have c(a/c)(A/G)(A/C)cAUGGCG as a consensus which exhibits an overall similarity with the vertebrate consensus. The experimental evidence regarding the importance of the AUG context in plants is discussed.