TY - JOUR
T1 - Identification of a regulated alkaline phosphatase, a cell surface-associated lipoprotein, in Mycobacterium smegmatis
AU - Kriakov, Jordan
AU - Lee, Sun Hee
AU - Jacobs, William R.
PY - 2003/8
Y1 - 2003/8
N2 - 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 [14C]acetate-labeled M. smegmatis cell lysates demonstrated that this phosphatase is a lipoprotein.
AB - 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 [14C]acetate-labeled M. smegmatis cell lysates demonstrated that this phosphatase is a lipoprotein.
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U2 - 10.1128/JB.185.16.4983-4991.2003
DO - 10.1128/JB.185.16.4983-4991.2003
M3 - Article
C2 - 12897018
AN - SCOPUS:0042532056
SN - 0021-9193
VL - 185
SP - 4983
EP - 4991
JO - Journal of bacteriology
JF - Journal of bacteriology
IS - 16
ER -