title: Structural basis for RNA recognition by NusB and NusE in the initiation of transcription antitermination.
abstract: Processive transcription antitermination requires the assembly of the complete antitermination complex, which is initiated by the formation of the ternary NusB-NusE-BoxA RNA complex. We have elucidated the crystal structure of this complex, demonstrating that the BoxA RNA is composed of 8 nt that are recognized by the NusB-NusE heterodimer. Functional biologic and biophysical data support the structural observations and establish the relative significance of key protein-protein and protein-RNA interactions. Further crystallographic investigation of a NusB-NusE-dsRNA complex reveals a heretofore unobserved dsRNA binding site contiguous with the BoxA binding site. We propose that the observed dsRNA represents BoxB RNA, as both single-stranded BoxA and double-stranded BoxB components are present in the classical lambda antitermination site. Combining these data with known interactions amongst antitermination factors suggests a specific model for the assembly of the complete antitermination complex.
authors.affiliation: Macromolecular Crystallography Laboratory, National Cancer Institute, Frederick, MD 21702, USA.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Stagno
authors.forename: Amanda S
authors.initials: AS
authors.lastname: Altieri
authors.forename: Mikhail
authors.initials: M
authors.lastname: Bubunenko
authors.forename: Sergey G
authors.initials: SG
authors.lastname: Tarasov
authors.forename: Jess
authors.initials: J
authors.lastname: Li
authors.forename: Donald L
authors.initials: DL
authors.lastname: Court
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Byrd
authors.forename: Xinhua
authors.initials: X
authors.lastname: Ji
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D001665:Binding Sites; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics; D005816:Genetic Complementation Test; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D055503:Protein Multimerization; D012313:RNA / Q000737:chemistry*; D012330:RNA, Double-Stranded / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics; D012269:Ribosomal Proteins / Q000737:chemistry* / Q000235:genetics; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; C074952:NusB protein, E coli; D012330:RNA, Double-Stranded; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; D014157:Transcription Factors; C064872:antiterminator proteins, Bacteria; C029537:ribosomal protein S10; D012313:RNA