The N‐terminus is unstructured, but not dynamically disordered, in the complex between HK022 Nun protein and λ‐phage BoxB RNA hairpin

FEBS Letters

Gottesman, Max E¹  Stuart, Ashley C¹  Palmer, Arthur G¹ 

[1] Department of Biochemistry and Molecular Biophysics, Columbia University, 630 West 168th Street, New York, NY 10032, USA

关键词: Transcription termination;    Dynamics;    Disordered protein;    Nuclear magnetic resonance spin relaxation;    Arginine-rich motif;   

DOI  :  10.1016/S0014-5793(03)00979-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The Nun protein of lambdoid phage HK022 excludes λ-phage superinfection by blocking expression of genes downstream from the λ nut sequences. Heteronuclear NMR studies have been performed on a Nun peptide comprising residues 1–49 bound to the nutR BoxB RNA. The pattern of ¹³C chemical shifts indicates that the arginine-rich motif of Nun forms an induced α-helix, consisting of residues 23–43, when bound to BoxB RNA, consistent with the structure of a shorter (residues 22–44) Nun peptide/BoxB RNA complex [Faber, C., Schärpf, M., Becker, T., Sticht, H. and Rösch (2001) J. Biol. Chem. 276, 32064–32070]. The N-terminal extension, residues 1–22, does not show chemical shifts or nuclear Overhauser effects characteristic of stable secondary structure. Nonetheless, ¹⁵N relaxation measurements indicate that this region is not completely disordered, as expected for a random coil peptide. Restriction of conformation flexibility in the N-terminal extension of Nun may be important for binding to other target molecules involved in transcription termination.

【 授权许可】

Unknown