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

Abstract

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.

Proteins from thermophilic microorganisms.

“…This behavior suggests some type of conformational change; however, the nature of this change is not understood at this time. (18). The peptide (comprising positions 4 to 20 of the prototype sequence) consists of 20 residues in contrast to 17 residues found in most glyceraldehyde-3-phosphate dehydrogenases.…”