Analysis of conformational changes in 16 S rRNA during the course of 30 S subunit assembly.
Ribosome biogenesis involves an integrated series of binding events coupled with conformational changes that ultimately result in the formation of a functional macromolecular complex. In vitro, Escherichia coli 30 S subunit assembly occurs in a cooperative manner with the ordered addition of 20 ribosomal proteins (r-proteins) with 16 S rRNA. The assembly pathway for 30 S subunits has been dissected in vitro into three steps, where specific r-proteins associate with 16 S rRNA early in 30 S subunit assembly, followed by a mid-assembly conformational rearrangement of the complex that then enables the remaining r-proteins to associate in the final step. Although the three steps of 30 S subunit assembly have been known for some time, few details have been elucidated about changes that occur as a result of these three specific stages. Here, we present a detailed analysis of the concerted early and late stages of small ribosomal subunit assembly. Conformational changes, roles for base-pairing and r-proteins at specific stages of assembly, and a polar nature to the assembly process have been revealed. This work has allowed a more comprehensive and global view of E.coli 30 S ribosomal subunit assembly to be obtained.
Holmes
Kristi L
KL
Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
Culver
Gloria M
GM
D020029:Base Pairing; D004926:Escherichia coli / Q000737:chemistry / Q000235:genetics; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D021122:Protein Subunits; D012329:RNA, Bacterial / Q000737:chemistry / Q000235:genetics; D012336:RNA, Ribosomal, 16S / Q000737:chemistry* / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism
D021122:Protein Subunits; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; D012269:Ribosomal Proteins; C040469:ribosomal protein S30