YEAST PHOSPHOGLYCERATE MUTASE - CYANOGEN-BROMIDE CLEAVAGE AND AMINO-ACID SEQUENCE OF AN ACTIVE-SITE PEPTIDE

The molecular weight and amino acid composition of phosphoglycerate mutase [EC-5.4.2.1] from yeast were determined. CNBr cleavage produced a large (190-residue) fragment and a small (60-residue) fragment. Tryptic and chymotryptic peptides derived from the large fragment were fractionated by ion-exchange chromatography. Peptides from 2 histidine-containing regions were isolated and the amino acid sequences determined. Correlation of these data with X-ray-crystallographic evidence shows that the histidine residue in the sequence Arg-Leu-Asn-Glu-Arg-His-Tyr-Gly-Asp-Leu-Glu-Gly-Lys is located at the active site.