Study of mycoloyl transferase transport across the cell envelope of Corynebacterium glutamicum

PS1 is a major exported protein of Corynebacterium glutamicum homologous to mycobacterial antigen 85. It is largely associated with the mycolic acid-c ontaining cell wall and acts as a mycoloyl transferase. The transport of PS 1 to the cell wall is slow and occurs through two energetically distinct st eps: the first one, which includes processing by signal peptidase, is rapid and inhibited by sodium azide or carbonyl cyanide m-chlorophenylhydrazone. This step is probably associated with translocation across the cytoplasmic membrane. The kinetics of the second step depend on the size of the polype ptide chain to be transported but neither ATP nor proton motive force is re quired. This step may correspond to the diffusion of PS1 across the cell wa ll to its final location. (C) 2001 Federation of European Microbiological S ocieties. Published by Elsevier Science B.V. All rights reserved.