Multiple pathways for primary processing of ribosomal RNA in Escherichia coli.
نویسندگان
چکیده
A comparison of isogenic RNase III+ and RNase III- strains of Escherichia coli shows that although both synthesize precursor and mature 16 S and 23 S ribosomal RNAs, the transient rRNA species of the RNase III- strain differ from those of the RNase III+ strain. The RNase III+ strain synthesizes p16 and p23 rRNA, whereas the RNase III- strain produces unstable 17 S, 18 S, "p23," 25 S and 30 S RNA molecules. The 30 S RNA, which is a primary transcript of the ribosomal RNA gene cluster, does not contribute significantly to any of the smaller RNAs, nor is m23 rRNA derived from 25 S but rather from "p23" RNA. Mature 16 S rRNA is derived from both 18 S and 17 S RNA, and 17 S RNA can be derived from 18 S. Additionally, an unstable RNA species about 300 bases long is missing in the RNase III- strain and another species which seems to be about 50 bases larger appears. Processing of the primary ribosomal RNA transcript in RNase III- strains of Escherichia coli is accomplished during its transcription by two independent pathways which are not so utilized in RNase III+ strains. One pathway yields 18 S and precursor 23 S RNAs which are processed to mature rRNAs; the second pathway yields 25 S RNA and perhaps 16 S rRNA. The second pathway, unlike the first, is inhibited by chloramphenicol treatment. At slow rates of ribosomal RNA synthesis, the nascent transcript is processed preferentially by the first pathway. We suggest that in the absence of RNase III, which is involved in the primary processing of rRNA in E. coli, other enzymes involved in primary and secondary processing of rRNA in RNase III+ cells can recognize their sites on the nascent rRNA transcript and accomplish the primary processing.
منابع مشابه
Multiple in vivo pathways for E. coli small ribosomal subunit assembly occur on one pre-rRNA
Processing of transcribed precursor ribosomal RNA (pre-rRNA) to a mature state is a conserved aspect of ribosome biogenesis in vivo. We developed an affinity purification system to isolate and analyze in vivo formed pre-rRNA containing ribonucleoprotein particles (rRNPs) from wild-type E. coli. We observed that the first processing intermediate of pre-SSU rRNA is a platform for biogenesis. Thes...
متن کاملCellular Morphology and Immunologic Properties of Escherichia coli Treated With Antimicrobial Antisense Peptide Nucleic Acid
Background & Objectives: Antisense peptide nucleic acids (PNA) that target growth essential genes show potent bactericidal properties without cell lysis. We considered the possibility that whether PNA treatment influence the bacteria total nucleic acids content and apply approach to develop a new delivery system to Dendritic cells (DCs). DCs are the most potent antigen presenting cells in th...
متن کاملDevelopment of 16S rRNA targeted PCR methods for the detection of Escherichia coli in Rainbow trout (Oncorhynchus mykiss)
Objectives: The presence of E.coli in fish intended for human consumption may constitute a potential danger, not only in causing disease, but also because of the possible transfer of antibiotic resistance from aquatic bacteria to those infecting humans. The objective of this study was to develop an improved PCR method based on species – specific 16 S rRNA gene primers (FES,...
متن کاملRNApathwaysDB—a database of RNA maturation and decay pathways
Many RNA molecules undergo complex maturation, involving e.g. excision from primary transcripts, removal of introns, post-transcriptional modification and polyadenylation. The level of mature, functional RNAs in the cell is controlled not only by the synthesis and maturation but also by degradation, which proceeds via many different routes. The systematization of data about RNA metabolic pathwa...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- The Journal of biological chemistry
دوره 252 9 شماره
صفحات -
تاریخ انتشار 1977