Crystal structure of bacteriophage lambda cII and its DNA complex.
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.
Jain
Deepti
D
The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
Kim
Youngchang
Y
Maxwell
Karen L
KL
Beasley
Steven
S
Zhang
Rongguang
R
Gussin
Gary N
GN
Edwards
Aled M
AM
Darst
Seth A
SA
D010582:Bacteriophage lambda / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004269:DNA, Bacterial / Q000737:chemistry*; D012321:DNA-Directed RNA Polymerases / Q000737:chemistry; D004926:Escherichia coli / Q000737:chemistry; D008958:Models, Molecular; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D014157:Transcription Factors / Q000737:chemistry*; D014764:Viral Proteins
D004269:DNA, Bacterial; D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda; D012321:DNA-Directed RNA Polymerases