Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.3 (RNase T1)
 1,228 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Analyses are described of three types of ribosomal fragment, all derived from the well-characterized ribonucleoprotein species consisting of proteins S7, S9, S10, S14 AND S19, together with RNA from sections O'-D-E'-K-P-P'-E-A of the 16-S sequence. 1. When 30-S subunits were hydrolysed with ribonuclease T1 in presence of deoxycholate in addition to the components previously described, a fragment could be isolated which contained only proteins S7 and S19, together with minor amounts of S13 or S14. Oligonucleotide analysis of this fragment showed that it contained RNA from sections O'-E' and P-A of the 16-S RNA, but that section K (from the middle of this area) was missing. 2. It has previously been shown that when 30-S subunits are irradiated with ultraviolet light, protein S7 is the primary target of cross-linking of protein to RNA. By making use of this reaction, ribonucleoprotein fragments were isolated from irradiated 30-S subunits the unbound proteins were removed, and RNA fragments containing covalently linked protein S7 were identified. It was possible to demonstrate that the site of cross-linking lies within the O'-A region of the 16-S RNA, and more precise experiments showed that this site almost certainly is in the P-A region. 3. When the parent five-protein ribonucleoprotein fragment (above) was deproteinized under very mild conditions, RNA complexes could be isolated which consisted of non-contiguous sequences, but which migrated as a single species into a polyacrylamide gel. Analysis of one of these complexes showed that it contained sequences from sections O'-E' and P-A, but that section K was missing (cf. first paragraph above). This demonstrated that these two separate regions of RNA interact within the 30-S subunit, independently of the presence of protein.
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PMID:Studies on the environment of protein S7 within the 30-S subunit Escherichia coli ribosomes. 77 16

1. A ribonucleoprotein fragment containing proteins S7, S9, S10, S14, and S19 was isolated in high yield from Escherichia coli 30-S ribosomal sub-particles. The same fragment was obtained whether ribosomes from E. coli strain A19 or MRE 600 were used, despite the fact that protein S7 differs widely between the two strains. RNA was extracted from this fragment and fractionated on gels containing 7 M urea, to reveal "hidden breaks". A well-defined and reporducible pattern of RNA fragments was obtained, with the main components being approximately 300, 240, 130, 115 and 75 nucleotides in length, respectively. The pattern of RNA fragments obtained was also independent of the strain of E. coli used. 2. Two-dimensional fingerprints were made from ribonuclease T1 hydrolysates of these RNA fragments, labelled with 32P, and the oligonucleotides were further analysed by digestion with either ribonuclease A or U2. The data obtained were fitted in detail to the new 16-S RNA sequence map of Ehresmann et al. (1975). Again no significant differences were observed between the RNA from E. coli A19 or MRE 600. The RNA sequences found lay in the region O'-D-E'-K-P-P'-E-A of the 16-S RNA, with a clear excision of several nucleotides in section E'-K. The total sequence length covered was approximately 430 nucleotides.
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PMID:Nucleotide sequences of Escherichia coli 16-S RNA associated with ribosomal proteins S7, S9, S10, S14 and S19. 110 Mar 89

We have investigated the transcription patterns at the inter-operon regions between the S10 and spc, and spc and alpha ribosomal protein operons of Escherichia coli. Newly synthesized transcripts were characterized by RNase T1 protection experiments, and accumulated transcripts were mapped with S1 nuclease. With both techniques we found that about 75% of the RNA polymerases transcribing the S10 operon terminated at the position of a typical rho-independent terminator. In contrast, most or all RNA polymerases transcribing the spc operon continued into the alpha operon. Nevertheless, we observed that about 30% of the transcripts of the alpha operon were initiated at the alpha operon promoter.
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PMID:Transcriptional organization of the S10, spc and alpha operons of Escherichia coli. 220 63