Open AccessRNA-protein cross-linking in Escherichia coli 30s ribosomal subunits: precise localisation of the nucleotide in 16s RNA which is coupled to protein S7 by ultraviolet irradiation
Author(s) -
Christian W Zwieb,
Richard Brimacornbe
Publication year - 1979
Publication title -
nucleic acids research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 9.008
H-Index - 537
eISSN - 1362-4954
pISSN - 0305-1048
DOI - 10.1093/nar/6.5.1775
Subject(s) - biology , 30s , ribosomal rna , rna , nucleic acid , escherichia coli , ribosomal protein , ribosome , nucleotide , microbiology and biotechnology , genetics , gene
It is well established that when E. coli 30S ribosomal subunits are irradiated with ultraviolet light under mild conditions a specific cross-link is formed between protein S7 and the 16S RNA. Methodology is presented for the analysis of the single nucleotide residue concerned in this cross-link. Firstly, the identity of the ribonuclease T1 octanucleotide attached to S7 is confirmed by a new method, which involves isolation and analysis of S7-polynucleotide complexes containing 30 -- 40 nucleotides. Secondly, the isolated S7-octanucleotide complex is digested successively with ribonuclease A, proteinase K and ribonuclease T2, and the nucleotides liberated are identified. The results show unambiguously that uridine residue number 1239 in the 16S RNA sequence is cross-linked to protein S7.