Bacillus SubtilisD‐AminopeptidaseDppA

Abstract

The D ‐aminopeptidase DppA, identified in Bacillus species, represents the prototype of a separate family of dinuclear zinc proteases. The catalytic domain of the enzyme comprises a Rossmann‐like α/β/α‐fold that coordinates two zinc ions near the C‐terminal edge of a six‐stranded parallel β‐sheet. Despite the lack in sequence and structural homology, the zinc coordination is highly similar to that found in established dinuclear zinc proteases. Furthermore, DppA forms a decameric molecule that encloses a central cavity that sequesters the 10 active sites. The architecture of the complex strongly resembles that found in a group of enzymes known as self‐compartmentalizing proteases, with bacterial and eukaryotic proteasomes as most characteristic examples.