A Novel Mechanism of Latency in Matrix Metalloproteinases

• Published in: The Journal of biological chemistry 2015-02, Vol.290 (8), p.4728-4740
• Main Authors: López-Pelegrín, Mar, Ksiazek, Miroslaw, Karim, Abdulkarim Y., Guevara, Tibisay, Arolas, Joan L., Potempa, Jan, Gomis-Rüth, F.Xavier
• Format: Article
• Language: English
• Subjects: Bacterial Proteins - chemistry; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Bacteroidaceae - enzymology; Bacteroidaceae - genetics; Bacteroides forsythus; Cysteine - chemistry; Cysteine - genetics; Cysteine - metabolism; Enzymology; Evolution, Molecular; Gene Transfer, Horizontal; Humans; Matrix Metalloproteinase (MMP); Matrix Metalloproteinases - chemistry; Matrix Metalloproteinases - genetics; Matrix Metalloproteinases - metabolism; Peptidase; Periodontal Disease; Periodontitis - enzymology; Periodontitis - genetics; Periodontitis - microbiology; Protease; Protein Evolution; Protein Folding; Protein Structure, Tertiary; X-ray Crystallography
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M114.605956

The matrix metalloproteinases (MMPs) are a family of secreted soluble or membrane-anchored multimodular peptidases regularly found in several paralogous copies in animals and plants, where they have multiple functions. The minimal consensus domain architecture comprises a signal peptide, a 60–90-residue globular prodomain with a conserved sequence motif including a cysteine engaged in “cysteine-switch” or “Velcro” mediated latency, and a catalytic domain. Karilysin, from the human periodontopathogen Tannerella forsythia, is the only bacterial MMP to have been characterized biochemically to date. It shares with eukaryotic forms the catalytic domain but none of the flanking domains. Instead of the consensus MMP prodomain, it features a 14-residue propeptide, the shortest reported for a metallopeptidase, which lacks cysteines. Here we determined the structure of a prokarilysin fragment encompassing the propeptide and the catalytic domain, and found that the former runs across the cleft in the opposite direction to a bound substrate and inhibits the latter through an “aspartate-switch” mechanism. This finding is reminiscent of latency maintenance in the otherwise unrelated astacin and fragilysin metallopeptidase families. In addition, in vivo and biochemical assays showed that the propeptide contributes to protein folding and stability. Our analysis of prokarilysin reveals a novel mechanism of latency and activation in MMPs. Finally, our findings support the view that the karilysin catalytic domain was co-opted by competent bacteria through horizontal gene transfer from a eukaryotic source, and later evolved in a specific bacterial environment. Background: Animal and plant matrix metalloproteinases (MMPs) are kept zymogenic through large prodomains and a cysteine-switch mechanism. Results: Bacterial MMP karilysin has only a short N-terminal peptide upstream of the catalytic domain, which lacks cysteines. Conclusion: This peptide inhibits through an aspartate-switch mechanism and also exerts other functions of authentic prodomains. Significance: Karilysin is kept latent by a novel mechanism for MMPs.