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J Biol Chem. 2008 Feb 1;283(5):2871-82. Epub 2007 Nov 9.

A new autocatalytic activation mechanism for cysteine proteases revealed by Prevotella intermedia interpain A.

Author information

1
Departament de Biologia Estructural, Institut de Biologia Molecular de Barcelona, Consejo Superior de Investigaciones Cientificas, c/Jordi Girona 18-26, Barcelona, Spain.

Abstract

Prevotella intermedia is a major periodontopathogen contributing to human gingivitis and periodontitis. Such pathogens release proteases as virulence factors that cause deterrence of host defenses and tissue destruction. A new cysteine protease from the cysteine-histidine-dyad class, interpain A, was studied in its zymogenic and self-processed mature forms. The latter consists of a bivalved moiety made up by two subdomains. In the structure of a catalytic cysteine-to-alanine zymogen variant, the right subdomain interacts with an unusual prodomain, thus contributing to latency. Unlike the catalytic cysteine residue, already in its competent conformation in the zymogen, the catalytic histidine is swung out from its active conformation and trapped in a cage shaped by a backing helix, a zymogenic hairpin, and a latency flap in the zymogen. Dramatic rearrangement of up to 20A of these elements triggered by a tryptophan switch occurs during activation and accounts for a new activation mechanism for proteolytic enzymes. These findings can be extrapolated to related potentially pathogenic cysteine proteases such as Streprococcus pyogenes SpeB and Porphyromonas gingivalis periodontain.

PMID:
17993455
PMCID:
PMC2772895
DOI:
10.1074/jbc.M708481200
[Indexed for MEDLINE]
Free PMC Article

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