Open AccessEvidence for the presence of two distinct phosphoenolpyruvate: Mannose phosphotransferase systems in Streptococcus mutans GS5‐2
Author(s) -
Néron Sonia,
Vadeboncoeur Christian
Publication year - 1987
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1987.tb02290.x
Subject(s) - mannose , pep group translocation , phosphoenolpyruvate carboxykinase , mutant , biochemistry , phosphotransferase , strain (injury) , biology , mannose 6 phosphate , mannose receptor , microbiology and biotechnology , chemistry , phosphorylation , enzyme , in vitro , gene , growth factor , receptor , anatomy , macrophage
We have isolated a spontaneous 2‐deoxyglucose (2DG) resistant mutant from Streptococcus mutans GS5‐2, called GM500, that grew as well as the parental strain on mannose. Membranes of glucose‐grown cells of the mutant strain were, however, unable to catalyse the phosphoenolpyruvate‐dependent phosphorylation of mannose in the presence of purified enzyme I (EI) and hydroxyproline (HPr) unlike the wild‐type cells. Resting cells of strain GM500 were also unable to transport mannose after growth at the expense of glucose, whereas glucose‐grown cells of strain GS5‐2 transported and metabolized mannose at a high rate. These activities were recovered in the mutant strain after growth on mannose. Our results indicate the presence of 2 phosphoenolpyruvate:mannose phosphotransferase systems in S. mutans GS5‐2. One system was constitutive and had a K s for mannose of 2.6 μM. The other system was inducible with a K s for mannose of 15 μM.