Open AccessTsp: a tail-specific protease that selectively degrades proteins with nonpolar C termini.
Author(s) -
Karen R. Silber,
Kenneth C. Keiler,
Robert Sauer
Publication year - 1992
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.89.1.295
Subject(s) - protease , biochemistry , peptide sequence , biology , escherichia coli , microbiology and biotechnology , gene , enzyme
An Escherichia coli protease designated Tsp (tail-specific protease) has been purified, and its gene has been cloned and sequenced. Tsp specifically degrades a variant of the N-terminal domain of lambda repressor in which the five C-terminal residues, which are polar in wild type, have been replaced by nonpolar residues. This substrate specificity in vitro parallels the previously reported selective degradation in vivo of N-terminal-domain variants with nonpolar C-terminal residues. The gene sequence and N-terminal protein sequence of Tsp predict a protein of 660 amino acids. The deduced protein sequence of Tsp shows no significant homology to known protease sequences but does show sequence similarity to the human and bovine interphotoreceptor retinoid-binding proteins, which bind hydrophobic ligands.