Identification of a regulated alkaline phosphatase, a cell surface-associated lipoprotein, in Mycobacterium smegmatis.

Journal Article (Journal Article)

Although alkaline phosphatases are common in a wide variety of bacteria, there has been no prior evidence for alkaline phosphatases in Mycobacterium smegmatis. Here we report that transposon insertions in the pst operon, encoding homologues of an inorganic phosphate transporter, leads to constitutive expression of a protein with alkaline phosphatase activity. DNA sequence analysis revealed that M. smegmatis does indeed have a phoA gene that shows high homology to other phoA genes. The M. smegmatis phoA gene was shown to be induced by phosphate starvation and thus negatively regulated by the pst operon. Interestingly, the putative M. smegmatis PhoA has a hydrophobic N-terminal domain which resembles a lipoprotein signal sequence. The M. smegmatis PhoA was demonstrated to be an exported protein associated with the cell surface. Furthermore, immunoprecipitation of PhoA from [(14)C]acetate-labeled M. smegmatis cell lysates demonstrated that this phosphatase is a lipoprotein.

Full Text

Cited Authors

  • Kriakov, J; Lee, SH; Jacobs, WR

Published Date

  • August 2003

Published In

Volume / Issue

  • 185 / 16

Start / End Page

  • 4983 - 4991

PubMed ID

  • 12897018

Pubmed Central ID

  • PMC166462

International Standard Serial Number (ISSN)

  • 0021-9193

Digital Object Identifier (DOI)

  • 10.1128/JB.185.16.4983-4991.2003


  • eng

Conference Location

  • United States