title: Protein L5 is crucial for in vivo assembly of the bacterial 50S ribosomal subunit central protuberance.
abstract: In the present work, ribosomes assembled in bacterial cells in the absence of essential ribosomal protein L5 were obtained. After arresting L5 synthesis, Escherichia coli cells divide a limited number of times. During this time, accumulation of defective large ribosomal subunits occurs. These 45S particles lack most of the central protuberance (CP) components (5S rRNA and proteins L5, L16, L18, L25, L27, L31, L33 and L35) and are not able to associate with the small ribosomal subunit. At the same time, 5S rRNA is found in the cytoplasm in complex with ribosomal proteins L18 and L25 at quantities equal to the amount of ribosomes. Thus, it is the first demonstration that protein L5 plays a key role in formation of the CP during assembly of the large ribosomal subunit in the bacterial cell. A possible model for the CP assembly in vivo is discussed in view of the data obtained.
authors: Institute of Protein Research, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia. korepan@vega.protres.ru
authors: Alexey P
authors: AP
authors: Korepanov
authors: Anna V
authors: AV
authors: Korobeinikova
authors: Sergey A
authors: SA
authors: Shestakov
authors: Maria B
authors: MB
authors: Garber
authors: George M
authors: GM
authors: Gongadze
mesh_terms: D004926:Escherichia coli / Q000235:genetics / Q000254:growth & development; D029968:Escherichia coli Proteins / Q000235:genetics / Q000502:physiology*; D017353:Gene Deletion; D008958:Models, Molecular; D012341:RNA, Ribosomal, 5S / Q000737:chemistry; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D054681:Ribosome Subunits, Large, Bacterial / Q000737:chemistry* / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D012341:RNA, Ribosomal, 5S; D012269:Ribosomal Proteins; C577033:RplE protein, E coli; C029742:ribosomal protein L5