3FZY

Crystal Structure of Pre-cleavage Form of Cysteine Protease Domain from Vibrio cholerae RtxA Toxin

Summary for 3FZY

• Entry DOI: 10.2210/pdb3fzy/pdb
• Related: 3EEB
• Descriptor: RTX toxin RtxA, INOSITOL HEXAKISPHOSPHATE, CHLORIDE ION, ... (5 entities in total)
• Functional Keywords: rtxa toxin, cpd, cysteine protease domain, pre-cleavage form, idp00167, structural genomics, center for structural genomics of infectious diseases, csgid, toxin
• Biological source: Vibrio cholerae
• Total number of polymer chains: 2
• Total formula weight: 52457.43

Authors

Shuvalova, L.,Minasov, G.,Prochazkova, K.,Satchell, K.J.F.,Anderson, W.F.,Center for Structural Genomics of Infectious Diseases (CSGID) (deposition date: 2009-01-26, release date: 2009-02-17, Last modification date: 2023-09-06)

Primary citation

Prochazkova, K.,Shuvalova, L.A.,Minasov, G.,Voburka, Z.,Anderson, W.F.,Satchell, K.J.
Structural and molecular mechanism for autoprocessing of MARTX toxin of Vibrio cholerae at multiple sites
J.Biol.Chem., 284:26557-26568, 2009

PubMed Abstract: The multifunctional autoprocessing repeats-in-toxin (MARTX) toxin of Vibrio cholerae causes destruction of the actin cytoskeleton by covalent cross-linking of actin and inactivation of Rho GTPases. The effector domains responsible for these activities are here shown to be independent proteins released from the large toxin by autoproteolysis catalyzed by an embedded cysteine protease domain (CPD). The CPD is activated upon binding inositol hexakisphosphate (InsP(6)). In this study, we demonstrated that InsP(6) is not simply an allosteric cofactor, but rather binding of InsP(6) stabilized the CPD structure, facilitating formation of the enzyme-substrate complex. The 1.95-A crystal structure of this InsP(6)-bound unprocessed form of CPD was determined and revealed the scissile bond Leu(3428)-Ala(3429) captured in the catalytic site. Upon processing at this site, CPD was converted to a form with 500-fold reduced affinity for InsP(6), but was reactivated for high affinity binding of InsP(6) by cooperative binding of both a new substrate and InsP(6). Reactivation of CPD allowed cleavage of the MARTX toxin at other sites, specifically at leucine residues between the effector domains. Processed CPD also cleaved other proteins in trans, including the leucine-rich protein YopM, demonstrating that it is a promiscuous leucine-specific protease.

PubMed: 19620709
DOI: 10.1074/jbc.M109.025510

Experimental method

X-RAY DIFFRACTION (1.95 Å)