Transcription Termination Factor Rho
From Proteopedia
Transcription termination factor Rho is a ring-shaped RNA-DNA helicase that induces release of transcription complexes at specific loci of bacterial genomes. Several structures of Rho in various liganded states haven been solved by X-ray crystallography by the J. M. Berger lab (Berkeley): 1a8v, 1pv4, 1pvo, 1xpr, 1xpu, 2a8v, and 2ht1.
The asymmetric unit solved as 2ht1 contains only two chains, so it represents only one third of the biological unit, which is a homo-hexamer. The scene here shows this homo-hexamer in a closed state ()[1]. Note that this model has only the middle 324 amino acids in each chain, lacking the first 52 and the last 57 amino acids in each chain[2].
In this model (), the Protein hexamer is bound to RNA, and some incidental "Solvent" (sulfate ions).
Here is one representation showing the same Rho hexamer in a closed state and with . In this scene, the foreground RNA is colored by element (C O N P). Also colored are Lys181, Lys283, Arg347, Arg353, and (in black) background RNA. See also Transcription and RNA Processing.
3D structures of helicase
Additional Resources
For additional information, see: Transcription and RNA Processing
Notes
- ↑ File Image:Rho1.pdb derived from 2ht1 by symmetry operations
- ↑ Missing residues can be found by aligning the PDB file's SEQRES records with the sequence of the residues assigned atomic coordinates, as listed by the S2C Server