title: Functional and molecular analysis of Escherichia coli strains lacking multiple DEAD-box helicases.
abstract: DEAD-box RNA helicases are enzymes that unwind RNA duplexes and are found in virtually all organisms. Most organisms harbor multiple DEAD-box helicases, suggesting that these factors participate in distinct aspects of RNA metabolism. To define the individual and collective contribution of the five DEAD-box helicases in the bacterium Escherichia coli (E. coli), nonpolar deletion mutants lacking single or multiple DEAD-box genes were constructed. An analysis of the single-deletion strains indicated that the absence of either the DeaD or SrmB RNA helicase causes growth and/or ribosomal defects under typical laboratory growth conditions. The analysis of strains lacking multiple DEAD-box genes showed cumulative growth defects at low temperatures. A strain deleted for all five DEAD-box genes was also constructed for these studies, representing the first time all DEAD-box genes have been removed in any organism. Additional investigations revealed that the growth and ribosomal defects of such a DEAD-box deficient strain can be sharply attenuated under alternative conditions, indicating that the defects caused by a lack of DEAD-box genes are modulated by growth context.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Jagessar
authors.forename: Chaitanya
authors.initials: C
authors.lastname: Jain
mesh_terms: D053487:DEAD-box RNA Helicases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D017384:Sequence Deletion
chemical_list: D053487:DEAD-box RNA Helicases