title: Crystallization and preliminary X-ray analysis of the ATPase domain of the σ(54)-dependent transcription activator NtrC1 from Aquifex aeolicus bound to the ATP analog ADP-BeFx.
abstract: One way that bacteria regulate the transcription of specific genes to adapt to environmental challenges is to use different σ factors that direct the RNA polymerase holoenzyme to distinct promoters. Unlike σ(70) RNA polymerase (RNAP), σ(54) RNAP is unable to initiate transcription without an activator: enhancer-binding protein (EBP). All EBPs contain one ATPase domain that belongs to the family of ATPases associated with various cellular activities (AAA+ ATPases). AAA+ ATPases use the energy of ATP hydrolysis to remodel different target macromolecules to perform distinct functions. These mechanochemical enzymes are known to form ring-shaped oligomers whose conformations strongly depend upon nucleotide status. Here, the crystallization of the AAA+ ATPase domain of an EBP from Aquifex aeolicus, NtrC1, in the presence of the non-hydrolyzable ATP analog ADP-BeFx is reported. X-ray diffraction data were collected from two crystals from two different protein fractions of the NtrC1 ATPase domain. Previously, this domain was co-crystallized with ADP and ATP, but the latter crystals were grown from the Walker B substitution variant E239A. Therefore, the new data sets are the first for a wild-type EBP ATPase domain co-crystallized with an ATP analog and they reveal a new crystal form. The resulting structure(s) will shed light on the mechanism of EBP-type transcription activators.
authors: Biochemistry and Molecular Biology, Penn State University, University Park, PA 16802, USA.
authors: Tatyana A
authors: TA
authors: Sysoeva
authors: Neela
authors: N
authors: Yennawar
authors: Marc
authors: M
authors: Allaire
authors: B Tracy
authors: BT
authors: Nixon
mesh_terms: D000251:Adenosine Triphosphatases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000737:chemistry*; D001419:Bacteria / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001608:Beryllium / Q000737:chemistry; D003460:Crystallization; D018360:Crystallography, X-Ray; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005459:Fluorides / Q000737:chemistry; D015870:Gene Expression; D017434:Protein Structure, Tertiary; D051877:RNA Polymerase Sigma 54 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; D011994:Recombinant Proteins; C035982:beryllium fluoride; D000255:Adenosine Triphosphate; D051877:RNA Polymerase Sigma 54; D000251:Adenosine Triphosphatases; D001608:Beryllium; D005459:Fluorides
keywords: AAA+ ATPases; Aquifex aeolicus; NtrC1; enhancer-binding protein; σ54 transcription activator