ClpX and ClpP are essential for the efficient acquisition of genes specifying type IA and IB restriction systems.
Efficient acquisition of genes that encode a restriction and modification (R-M) system with specificities different from any already present in the recipient bacterium requires the sequential production of the new modification enzyme followed by the restriction activity in order that the chromosome of the recipient bacterium is protected against attack by the restriction endonuclease. We show that ClpX and ClpP, the components of ClpXP protease, are necessary for the efficient transmission of the genes encoding EcoKI and EcoAI, representatives of two families of type I R-M systems, thus implicating ClpXP in the modulation of restriction activity. Loss of ClpX imposed a bigger barrier than loss of ClpP, consistent with a dual role for ClpX, possibly as a chaperone and as a component of the ClpXP protease. Transmission of genes specifying EcoKI was more dependent on ClpX and ClpP than transmission of the genes for EcoAI. Sensitivity to absence of the protease was also influenced by the mode of gene transfer; conjugative transfer and transformation were more dependent on ClpXP than transduction. In the absence of either ClpX or ClpP transfer of the EcoKI genes by P1-mediated transduction was impaired, transfer of the EcoAI genes was not.
Makovets
S
S
Institute of Cell and Molecular Biology, University of Edinburgh, UK.
Titheradge
A J
AJ
Murray
N E
NE
D049069:ATP-Dependent Proteases; D000074183:ATPases Associated with Diverse Cellular Activities; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics; D003090:Coliphages / Q000235:genetics; D003227:Conjugation, Genetic; D004262:DNA Restriction Enzymes / Q000235:genetics*; D015253:Deoxyribonucleases, Type I Site-Specific / Q000235:genetics*; D049071:Endopeptidase Clp; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D008565:Membrane Proteins / Q000235:genetics; D018832:Molecular Chaperones; D010957:Plasmids / Q000235:genetics; D012697:Serine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D014161:Transduction, Genetic; D014169:Transformation, Bacterial
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D018832:Molecular Chaperones; D004262:DNA Restriction Enzymes; C040446:endodeoxyribonuclease EcoAI; C089629:endodeoxyribonuclease EcoKI; D015253:Deoxyribonucleases, Type I Site-Specific; D049069:ATP-Dependent Proteases; C513383:FtsH protein, E coli; D012697:Serine Endopeptidases; C483573:ClpXP protease, E coli; D049071:Endopeptidase Clp; D000251:Adenosine Triphosphatases; C088072:ClpX protein, E coli; D000074183:ATPases Associated with Diverse Cellular Activities