Complete amino acid sequence of beta-tubulin from porcine brain.

The primary structure of porcine brain beta-tubulin was determined by automated and manual Edman degradation of six sets of overlapping peptides. The protein consists of 445 amino acid residues and has a minimum of six positions that are heterogeneous, indicating at least two beta-tubulins in porcine brain. Comparison of the optimally aligned sequences of alpha-tubulin and beta-tubulin indicates that 41% of their primary structures are identical. A region rich in glycyl residues is similar both in sequence and predicted secondary structure to the phosphate binding loop of several nucleotide binding enzymes. beta-Tubulin contains a highly acidic COOH-terminal region that resembles the NH2-terminus of troponin T.