Premium
The E. coli NusA carboxy‐terminal domains are structurally similar and show specific RNAP‐ and λN interaction
Author(s) -
Eisenmann Anke,
Schwarz Sabine,
Prasch Stefan,
Schweimer Kristian,
Rösch Paul
Publication year - 2005
Publication title -
protein science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.353
H-Index - 175
eISSN - 1469-896X
pISSN - 0961-8368
DOI - 10.1110/ps.051372205
Subject(s) - ctd , escherichia coli , heteronuclear single quantum coherence spectroscopy , protein subunit , titration , rna polymerase , crystallography , dna , binding site , biology , chemistry , nuclear magnetic resonance spectroscopy , protein–protein interaction , biophysics , stereochemistry , biochemistry , gene , inorganic chemistry , oceanography , geology
The carboxy‐terminal domain of the transcription factor Escherichia coli NusA, NusACTD, interacts with the protein N of bacteriophage λ, λN, and the carboxyl terminus of the E. coli RNA polymerase α subunit, αCTD. We solved the solution structure of the unbound NusACTD with high‐resolution nuclear magnetic resonance (NMR). Additionally, we investigated the binding sites of λN and αCTD on NusACTD using NMR titrations. The solution structure of NusACTD shows two structurally similar subdomains, NusA(353–416) and NusA(431–490), matching approximately two homologous acidic sequence repeats. Further characterization of NusACTD with 15 N NMR relaxation data suggests that the interdomain region is only weakly structured and that the subdomains are not interacting. Both subdomains adopt an (HhH) 2 fold. These folds are normally involved in DNA–protein and protein–protein interactions. NMR titration experiments show clear differences of the interactions of these two domains with αCTD and λN, in spite of their structural similarity.