The AprX protein of Pseudomonas aeruginosa: a new substrate for the Apr type I secretion system

Protein secretion in Pseudomonas aeruginosa involves different mechanisms. The type II and type III secretory pathways control the extracellular relea se of a wide range of substrates. The type I secretion process, or ABC tran sporter, was believed to be exclusively involved in alkaline protease secre tion. Recently, it was discovered that a P. aeruginosa heme binding protein , HasAp, is also secreted by a type I process. We present here the identifi cation of a third putative type I-dependent protein of P. aeruginosa,. AprX . The function of this protein has not yet been elucidated but very interes tingly it appears to be linked to the apr cluster, and organized in one sin gle operon together with the aprD, -E and -F genes. (C) 2001 Elsevier Scien ce B.V. All rights reserved.