title: Time course of large ribosomal subunit assembly in E. coli cells overexpressing a helicase inactive DbpA protein.
abstract: DbpA is a DEAD-box RNA helicase implicated in Escherichia coli large ribosomal subunit assembly. Previous studies have shown that when the ATPase and helicase inactive DbpA construct, R331A, is expressed in E. coli cells, a large ribosomal subunit intermediate accumulates. The large subunit intermediate migrates as a 45S particle in a sucrose gradient. Here, using a number of structural and fluorescent assays, we investigate the ribosome profiles of cells lacking wild-type DbpA and overexpressing the R331A DbpA construct. Our data show that in addition to the 45S particle previously described, 27S and 35S particles are also present in the ribosome profiles of cells overexpressing R331A DbpA. The 27S, 35S, and 45S independently convert to the 50S subunit, suggesting that ribosome assembly in the presence of R331A and the absence of wild-type DbpA occurs via multiple pathways.
authors.affiliation: Department of Chemistry, University of Central Florida, Orlando, Florida 32816, USA.
authors.forename: Riley C
authors.initials: RC
authors.lastname: Gentry
authors.affiliation: Department of Chemistry, University of Central Florida, Orlando, Florida 32816, USA.
authors.forename: Jared J
authors.initials: JJ
authors.lastname: Childs
authors.affiliation: Central Valley Toxicology, Clovis, California 93611, USA.
authors.forename: Jirair
authors.initials: J
authors.lastname: Gevorkyan
authors.affiliation: Department of Chemistry, University of Central Florida, Orlando, Florida 32816, USA.
authors.forename: Yulia V
authors.initials: YV
authors.lastname: Gerasimova
authors.affiliation: Department of Chemistry, University of Central Florida, Orlando, Florida 32816, USA.
authors.forename: Eda
authors.initials: E
authors.lastname: Koculi
mesh_terms: D053487:DEAD-box RNA Helicases / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D007700:Kinetics; D012329:RNA, Bacterial / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D012270:Ribosomes
chemical_list: D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; C065908:dbpA protein, E coli; D053487:DEAD-box RNA Helicases
keywords: DEAD-box protein; DbpA; RNA helicase; ribosome assembly; ribosome maturation factor