Amino Acid Sequence Around the Catalytic Site in Glyceraldehyde-3-Phosphate Dehydrogenase from Bacillus stearothermophilus.

The tryptic peptide containing the active-site cysteine in glyceraldehyde-3-phosphate dehydrogenase from Bacillus stearothermophilus 1503 was isolated after inhibition of the enzyme with (14)C-iodoacetate. The amino acid sequence of the 20-residue peptide was determined by 19 successive cycles of dansyl-Edman degradation. The sequence shows considerable homology with its counterparts from mesophilic sources but differs by the addition of Ala-His-His at the N-terminus and by the substitution of phenylalanine for leucine in the prototype sequence.