Pentapeptide regulation of aspartyl-phosphate phosphatases

Aspartyl-phosphate phosphatases are integral components of the phosphorelay signal transduction system for sporulation initiation in Bacillus subtilis . The Rap and Spo0E families of protein phosphatases specifically dephospho rylate the sporulation response regulators Spo0F and Spo0A, respectively. T he phosphatases interpret regulatory signals antithetical to sporulation an d the Rap phosphatases are subject to inactivation by specific pentapeptide s. generated from an inactive peptide precursor. Additional regulatory sign als are brought about by the complex activation circuit that generates the Phr pentapeptide inhibitors of Rap phosphatases. Phr peptide's recognition of the Rap phosphatase targets is remarkably specific. Specificity is dicta ted by the amino acid sequence of the pentapeptide. The identification of t etratricopeptide repeats in the Rap proteins may explain the mechanism by w hich Phr peptides bind to and inhibit the activity of Rap phosphatases. (C) 2001 Elsevier Science Inc. All rights reserved.