title: Crystal structure of bacteriophage lambda cII and its DNA complex.
abstract: 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.
authors.affiliation: The Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
authors.forename: Deepti
authors.initials: D
authors.lastname: Jain
authors.forename: Youngchang
authors.initials: Y
authors.lastname: Kim
authors.forename: Karen L
authors.initials: KL
authors.lastname: Maxwell
authors.forename: Steven
authors.initials: S
authors.lastname: Beasley
authors.forename: Rongguang
authors.initials: R
authors.lastname: Zhang
authors.forename: Gary N
authors.initials: GN
authors.lastname: Gussin
authors.forename: Aled M
authors.initials: AM
authors.lastname: Edwards
authors.forename: Seth A
authors.initials: SA
authors.lastname: Darst
mesh_terms: 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
chemical_list: D004269:DNA, Bacterial; D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda; D012321:DNA-Directed RNA Polymerases