Nucleotide and corresponding amino acid sequences encoded by α and β tubulin mRNAs

Most of the mRNA sequences coding for α and β tubulin in embryonic chick brain have been determined by sequencing of cloned cDNA copies of these mRNAs. From a 1,682-base pair cDNA sequence we have deduced the entire protein sequence for β tubulin. For α tubulin, all but about 38 N-terminal amino acids have been deduced from the cDNA sequence. Although tyrosine has previously been shown to be post-translationally added to the C-terminus of α tubulin by a specific ligase, we conclude that the primary post-translational event must be the removal, not the addition, of tyrosine because a terminal tyrosine is encoded by the mRNA.