COMPLETE AMINO-ACID-SEQUENCE AND COMPARATIVE MOLECULAR MODELING OF HPR FROM STREPTOCOCCUS-MUTANS INGBRITT

The heat-stable phosphocarrier protein (HPr) of Streptococcus mutans w as extracted from whole cells using sodium lauroylsarcosinate/EDTA and purified to homogeneity by a single-step, ion-exchange chromatographi c procedure. The complete amino acid sequence of the protein was deter mined from peptides generated by trypsin, alpha-chymotrypsin, endoprot einase Glu-C, and cyanogen bromide treatment. The HPr from S. mutans c ontains 86 or 87 amino acyl residues, depending on removal of the N-te rminal Met and the protein shows high sequence homology with HPr from other Gram-positive bacteria. The predicted tertiary structure of the S. mutans HPr, from model building by homology, is an open-faced beta- sandwich consisting of two alpha-helices and a four-stranded antiparal lel beta-sheet. (C) 1994 Academic Press, Inc.