Molecular Playground/4'-PHOSPHOPANTETHEINYL TRANSFERASE (Sfp)

Introduction

Sfp is a 4'-phosphopantetheinyl (PPant) transferase endogenous to B. Subtilis, first crystallized in 1999 [1]. The function of Sfp is to transfer a phosphopantetheinyl group from coenzyme-A (CoA-SH) to the serine residue of peptides containing the sequence "DSL". Frequently this sequence is found in acyl- or peptidyl-carrier proteins in fatty acid synthases (FASs), polyketide synthases (PKSs), and nonribosomal peptide synthetases (NRPSs). This posttranslational modification converts the inactive apo form peptide to the active holo form. The terminal thiol PPant prosthetic group acts as a point of covalent attachment between the peptide and the growing fatty acid, polyketide, or nonribosomal peptide.

Mechanism of Transfer

Active site magnesium along with ATP are involved in the catalytic transformation of the apo proteins.

Biochemical Applications