Pasteurellaceae ComE1 proteins combine the properties of fibronectin adhesins and DNA binding competence proteins.
A novel fibronectin-binding protein from Pasteurella multocida (PM1665) that binds to the fibronectin type III(9-10) modules via two helix-hairpin-helix motifs has recently been described [1]. This protein shares homology with competence-related DNA-binding and uptake proteins (ComEA and ComE) from Gram-positive and Gram-negative bacteria. Here, we show that recombinant PM1665 (now designated ComE1) also binds to DNA through the same helix-hairpin-helix motifs required for fibronectin-binding. This binding to DNA is non sequence-specific and is confined to double-stranded DNA. We have cloned and expressed ComE1 proteins from five members of the Pasteurellaceae in order to further investigate the function(s) of these proteins. When expressed as recombinant GST-fusion proteins, all of the homologues bound both to fibronectin and to double-stranded DNA. Inactivation of the gene encoding the ComE1 homologue in Actinobacillus pleuropneumoniae indicates major roles for these proteins in at least two processes: natural transformation, and binding of bacteria to fibronectin.
Mullen
Lisa M
LM
Division of Microbial Diseases, UCL Eastman Dental Institute, University College London, London, United Kingdom. l.mullen@eastman.ucl.ac.uk
Bossé
Janine T
JT
Nair
Sean P
SP
Ward
John M
JM
Rycroft
Andrew N
AN
Robertson
Giles
G
Langford
Paul R
PR
Henderson
Brian
B
D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005353:Fibronectins / Q000378:metabolism*; D006801:Humans; D015661:Pasteurellaceae / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D020349:Surface Plasmon Resonance
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D005353:Fibronectins; D011993:Recombinant Fusion Proteins; D004247:DNA