Open AccessActA is a dimer
Author(s) -
Philippe Mourrain,
Íñigo Lasa,
Alexis Gautreau,
Edith Gouin,
Anthony P. Pugsley,
Pascale Cossart
Publication year - 1997
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.94.19.10034
Subject(s) - dimer , listeria monocytogenes , actin , polymerization , chemistry , bacteria , domain (mathematical analysis) , yeast , cytosol , biophysics , microbiology and biotechnology , biology , biochemistry , genetics , polymer , enzyme , mathematical analysis , mathematics , organic chemistry
ActA, a surface protein of Listeria monocytogenes, is able to induce continuous actin polymerization at the rear of the bacterium, in the cytosol of the infected cells. Its N-terminal domain is sufficient to induce actin tail formation and movement. Here, we demonstrate, using the yeast two-hybrid system, that the N-terminal domain of ActA may form homodimers. By using chemical cross-linking to explore the possibility that ActA could be a multimer on the surface of the bacteria, we show that ActA is a dimer. Cross-linking experiments on various L. monocytogenes strains expressing different ActA variants demonstrated that the region spanning amino acids 97-126, and previously identified as critical for actin tail formation, is also critical for dimer formation. A model of actin polymerization by L. monocytogenes, involving the ActA dimer, is presented.