DnaAcos hyperinitiates by circumventing regulatory pathways that control the frequency of initiation in Escherichia coli. Export

@article{citeulike:4864334, abstract = {Mutants of dnaAcos are inviable at 30 degrees C because DnaAcos hyperinitiates, leading to new replication forks that apparently collide from behind with stalled forks, thereby generating lethal double-strand breaks. By comparison, an elevated level of DnaA also induces extra initiations, but lethality occurs only in strains defective in repairing double-strand breaks. To explore the model that the chromosomal level of DnaAcos, or the increased abundance of DnaA, increases initiation frequency by, escaping or overcoming pathways that control initiation, respectively, we developed a genetic selection and identified seqA, datA, dnaN and hda, which function in pathways that either act at oriC or modulate DnaA activity. To assess each pathway's relative effectiveness, we used genetically inactivated strains, and quantified initiation frequency after elevating the level of DnaA. The results indicate that the hda-dependent pathway has a stronger effect on initiation than pathways involving seqA and datA. Testing the model that DnaAcos overinitiates because it fails to respond to one or more regulatory mechanisms, we show that dnaAcos is unresponsive to hda and dnaN, which encodes the beta clamp, and also datA, a locus proposed to titer excess DnaA. These results explain how DnaAcos hyperinitiates to interfere with viability.}, author = {Felczak, Magdalena M. and Kaguni, Jon M.}, citeulike-article-id = {4864334}, citeulike-linkout-0 = {http://dx.doi.org/10.1111/j.1365-2958.2009.06724.x}, citeulike-linkout-1 = {http://www.ingentaconnect.com/content/bsc/mole/2009/00000072/00000006/art00005}, citeulike-linkout-2 = {http://view.ncbi.nlm.nih.gov/pubmed/19432804}, citeulike-linkout-3 = {http://www.hubmed.org/display.cgi?uids=19432804}, doi = {10.1111/j.1365-2958.2009.06724.x}, issn = {1365-2958}, journal = {Molecular microbiology}, keywords = {dnaa, dnaacos, genetic\_selection, initiation, oric, regulatory\_mechanisms}, month = {June}, number = {6}, pages = {1348--1363}, posted-at = {2009-10-12 20:28:26}, priority = {4}, publisher = {Blackwell Publishing}, title = {DnaAcos hyperinitiates by circumventing regulatory pathways that control the frequency of initiation in Escherichia coli.}, url = {http://dx.doi.org/10.1111/j.1365-2958.2009.06724.x}, volume = {72}, year = {2009} }

TY - JOUR ID - citeulike:4864334 L3 - citeulike-article-id:4864334 N2 - Mutants of dnaAcos are inviable at 30 degrees C because DnaAcos hyperinitiates, leading to new replication forks that apparently collide from behind with stalled forks, thereby generating lethal double-strand breaks. By comparison, an elevated level of DnaA also induces extra initiations, but lethality occurs only in strains defective in repairing double-strand breaks. To explore the model that the chromosomal level of DnaAcos, or the increased abundance of DnaA, increases initiation frequency by, escaping or overcoming pathways that control initiation, respectively, we developed a genetic selection and identified seqA, datA, dnaN and hda, which function in pathways that either act at oriC or modulate DnaA activity. To assess each pathway's relative effectiveness, we used genetically inactivated strains, and quantified initiation frequency after elevating the level of DnaA. The results indicate that the hda-dependent pathway has a stronger effect on initiation than pathways involving seqA and datA. Testing the model that DnaAcos overinitiates because it fails to respond to one or more regulatory mechanisms, we show that dnaAcos is unresponsive to hda and dnaN, which encodes the beta clamp, and also datA, a locus proposed to titer excess DnaA. These results explain how DnaAcos hyperinitiates to interfere with viability. IS - 6 JF - Molecular microbiology SN - 1365-2958 EP - 1363 TI - DnaAcos hyperinitiates by circumventing regulatory pathways that control the frequency of initiation in Escherichia coli. PB - Blackwell Publishing VL - 72 SP - 1348 KW - dnaa KW - dnaacos KW - genetic_selection KW - initiation KW - oric KW - regulatory_mechanisms AU - Felczak, Magdalena AU - Kaguni, Jon PY - 2009/06// UR - http://dx.doi.org/10.1111/j.1365-2958.2009.06724.x ER -