1ZPQ: Structure Of Bacteriophage Lambda Cii Protein

The tetrameric cII protein from bacteriophage lambda activates transcription from the phage promoters P(RE), P(I), and P(AQ) by binding to two direct repeats that flank the promoter -35 element. Here, we present the X-ray crystal structure of cII alone (2.8 A resolution) and in complex with its DNA operator from P(RE) (1.7 A resolution). The structures provide a basis for modeling of the activation complex with the RNA polymerase holoenzyme, and point to the key role for the RNA polymerase alpha subunit C-terminal domain (alphaCTD) in cII-dependent activation, which forms a bridge of protein/protein interactions between cII and the RNA polymerase sigma subunit. The model makes specific predictions for protein/protein interactions between cII and alphaCTD, and between alphaCTD and sigma, which are supported by previous genetic studies.
PDB ID: 1ZPQDownload
MMDB ID: 34746
PDB Deposition Date: 2005/5/17
Updated in MMDB: 2006/12
Experimental Method:
x-ray diffraction
Resolution: 2.8  Å
Source Organism:
Similar Structures:
Biological Unit for 1ZPQ: tetrameric; determined by author and by software (PISA)
Molecular Components in 1ZPQ
Label Count Molecule
Proteins (4 molecules)
Regulatory Protein CII(Gene symbol: cII)
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB