Open AccessFunctional analysis of exotoxin A‐related protein of Pseudomonas aeruginosa lacking residues 225–412
Author(s) -
GuidiRontani Chantal
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04644.x
Subject(s) - pseudomonas exotoxin , pseudomonas aeruginosa , exotoxin , elongation factor , internalization , transferase , domain (mathematical analysis) , chemistry , toxin , biochemistry , biology , gene , receptor , recombinant dna , enzyme , genetics , bacteria , ribosome , mathematical analysis , rna , mathematics
Summary The crystal structure of the exotoxin A (ETA) of Pseudomonas aeruginosa showed that this protein is folded into three distinct domains. Domain I (Ia and Ib), the amino‐terminal domain, is the receptor‐binding domain of ETA and domain III, the carboxy‐terminal domain, is responsible for the ADP‐ribosyl transferase activity of the toxin. To elucidate the function(s) of domains 1b and II in the intoxication process and to define the region of the domain III necessary for ADP‐ribosylating activity, a defined deletion in the structural gene of P. aeruginosa ETA encompassing resdiues 225–412 was constructed and an ETA‐related product DeID, (from which all of domains II and Ib were deleted) was expressed. The ETA‐related protein did not penetrate sensitive cells, but retained the same specific activity to ADP‐ribosylate elongation factor‐2 as wild‐type toxin. This suggests that domain II is necessary to allow toxin internalization by sensitive cells and that the absence of domain Ib does not interfere with enzymic activity. The domain strictly involved in ADP‐ribosylation activity encompasses residues 412–613.