title: Secondary structure mapping of an RNA ligand that has high affinity for the MetJ repressor protein and interference modification analysis of the protein-RNA complex.
abstract: The secondary structure of an RNA aptamer, which has a high affinity for the Escherichia coli MetJ repressor protein, has been mapped using ribonucleases and with diethyl pyrocarbonate. The RNA ligand is composed of a stem-loop with a highly structured internal loop. Interference modification showed that the bases within the internal loop, and those directly adjacent to it, are important in the binding of the RNA ligand to MetJ. Most of the terminal stem-loop could be removed with little effect on the binding. Ethylation interference suggests that none of the phosphate groups are absolutely essential for tight binding. The data suggest that the MetJ binding site on the aptamer is distinct from that of the natural DNA target, the 8-base pair Met box.
authors.affiliation: Department of Biochemistry and Genetics, The University of Newcastle, Newcastle upon Tyne, NE2 4HH, United Kingdom.
authors.forename: A
authors.initials: A
authors.lastname: McGregor
authors.forename: J B
authors.initials: JB
authors.lastname: Murray
authors.forename: C J
authors.initials: CJ
authors.lastname: Adams
authors.forename: P G
authors.initials: PG
authors.lastname: Stockley
authors.forename: B A
authors.initials: BA
authors.lastname: Connolly
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D029968:Escherichia coli Proteins; D010710:Phosphates / Q000737:chemistry; D010777:Photochemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012313:RNA / Q000737:chemistry; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism*; D012996:Solutions; D013891:Thiouridine / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D010710:Phosphates; D016601:RNA-Binding Proteins; D012097:Repressor Proteins; D012996:Solutions; C060486:methionine repressor protein, Bacteria; C489220:methionine repressor protein, E coli; D013891:Thiouridine; D012313:RNA