A comparison between the nucleotide sequences of the T4 IC32.1 - 32 and RB69 IC59 - 32 regions. These 2 regions contain determinants for translation initiation of the respective phage-induced mRNAs for gp32. The chart emphasizes sequence differences (entered as lettered residues in the RB69 sequence) between the 2 regions. The dashes indicate identity between RB69 and T4 residues. Sequence elements contributing to RNA pseudoknot formation in the T4 gene 32-specific mRNA are marked by horizontal arrows. Note the sequence overlap between elements of the pseudoknot and ORF32.1 (segG) of the T4 sequence. Also, see Fig 6 for a summary of properties of the RB69 sequence.