General and Regulatory Proteolysis in Corynebacteria
Johannes Amon, Alja Lüdke, Fritz Titgemeyer, and Andreas Burkovski
from: Corynebacteria: Genomics and Molecular Biology (Edited by: Andreas Burkovski). Caister Academic Press, U.K. (2008)
Proteases comprise a broad variety of functions in cells. They are involved in the degradation of polypeptides to supply amino acids for the synthesis of new proteins or for catabolism as carbon and energy source. Others remove misfolded or denatured proteins or are involved in the maturation of preproteins, the removal of signal peptides, and in the regulatory proteolysis of signal transduction proteins or transcriptional regulators. Furthermore, in pathogens, proteases are also important virulence factors. Reflecting this multiplicity of functions, in bacteria typically a broad set of proteases can be found. The composition of this set of proteolytic enzymes is specific for a single bacterium and depends on the ecological niche inhabited. This review focuses on the role of proteases in corynebacteria. The proteolytic equipment of the sequenced Corynebacterium species is compared to the number of proteases in other important groups of Gram-positive bacteria, namely bacilli, streptomycetes, and mycobacteria. Recent data on the Corynebacterium glutamicum Clp and FtsH protease complexes are summarized and the putative role of secreted and surface-anchored proteases in pathogenic corynebacteria, especially in Corynebacterium diphtheriae, is discussed read more ...