Facile One-Step Assembly of Bona Fide SUMO Conjugates by Chemoenzymatic Ligation.

The post-translational conjugation of the small ubiquitin-like modifiers (SUMOs) to target proteins occurs through a complex machinery that involves sequential action of at least three enzymes. SUMOylation performs crucial regulatory functions in several cellular processes. The availability of well-defined SUMO conjugates is necessary for untangling the mechanism of SUMOylation.

Structure and specificity of a new class of Ca-independent housekeeping sortase from provide insights into its non-canonical substrate preference.

Surface proteins in Gram-positive bacteria are incorporated into the cell wall through a peptide ligation reaction catalyzed by transpeptidase sortase. Six main classes (A-F) of sortase have been identified of which class A sortase is meant for housekeeping functions. The prototypic housekeeping sortase A (SaSrtA) from cleaves LPTG-containing proteins at the scissile T-G peptide bond and ligates protein-LPT to the terminal Gly residue of the nascent cross-bridge of peptidoglycan lipid II precursor.

Sorting of LPXTG peptides by archetypal sortase A: role of invariant substrate residues in modulating the enzyme dynamics and conformational signature of a productive substrate.

Transpeptidase sortase catalyzes the covalent anchoring of surface proteins to the cell wall in Gram-positive bacteria. Sortase A (SrtA) of Staphylococcus aureus is a prototype enzyme and considered a bona fide drug target because several substrate proteins are virulence-related and implicated in pathogenesis. Besides, SrtA also works as a versatile tool in protein engineering.