STRUCTURE-FUNCTION RELATIONSHIP OF TYPE-IV PREPILIN PEPTIDASE OF PSEUDOMONAS-AERUGINOSA - A REVIEW

The bifunctional enzyme prepilin peptidase (PilD) from Pseudomonas aer uginosa is a key determinant in both type-IV pilus biogenesis and extr acellular protein secretion, in its roles as a leader peptidase and MT ase. It is responsible for endopeptidic cleavage of the unique leader peptides that characterize type-IV pilin precursors, as well as protei ns with homologous leader sequences that are essential components of t he general secretion pathway found in a variety of Gram-negative patho gens. Following removal of the leader peptides, the same enzyme is res ponsible for the second posttranslational modification that characteri zes the type-IV pilins and their homologues, namely N-methylation of t he newly exposed N-terminal amino acid residue. This review discusses some of the work begun in order to answer questions regarding the stru cture-function relationships of the active sites of this unique enzyme . (C) 1997 Elsevier Science B.V.