LPXTGase refers to an endopeptidase enzyme from
Streptococci
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs ...
and
Staphylococci
''Staphylococcus'' is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. ''Staphylococcus'' species are facultative ...
with the capacity to cleave the carboxy-terminal LPXTG anchor motif of surface proteins similar to
Sortase
Sortase refers to a group of prokaryotic enzymes that modify surface proteins by recognizing and cleaving a carboxyl-terminal sorting signal. For most substrates of sortase enzymes, the recognition signal consists of the motif LPXTG (Leu-Pro-any ...
. However, LPXTGase differs significantly from
Sortase
Sortase refers to a group of prokaryotic enzymes that modify surface proteins by recognizing and cleaving a carboxyl-terminal sorting signal. For most substrates of sortase enzymes, the recognition signal consists of the motif LPXTG (Leu-Pro-any ...
in several ways: a) it is glycosylated, b) it contains unconventional amino acids, and c) it contains D-amino acids. The latter two characteristics indicate that ribosomes are not involve in the synthesis of LPXTGase. Data suggest that the enzymes responsible for cell wall assembly also assemble LPXTGase.
This is the first enzyme of its kind ever reported and was discovered in
streptococcal
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occur ...
and
staphylococcal
''Staphylococcus'' is a genus of Gram-positive bacteria in the family Staphylococcaceae from the order Bacillales. Under the microscope, they appear spherical (cocci), and form in grape-like clusters. ''Staphylococcus'' species are facultative ...
lysates due to its high cleavage activity for the LPXTG sequence (200x more active than
sortase
Sortase refers to a group of prokaryotic enzymes that modify surface proteins by recognizing and cleaving a carboxyl-terminal sorting signal. For most substrates of sortase enzymes, the recognition signal consists of the motif LPXTG (Leu-Pro-any ...
). While there are only three publications describing this enzyme, all from the same source, they are in high quality peer reviewed journals. One reason for this limitation is that there is no single gene that codes for LPXTGase (it does not fit the "one gene one enzyme" theory) making its manipulation purely biochemical. Thus, reproducibility from other sources is a slow limiting process.
References
{{Reflist
Enzymes
Membrane proteins