title: Crystallization and preliminary X-ray diffraction analysis of the Pax9 paired domain bound to a DC5 enhancer DNA element.
abstract: Pax genes belong to a family of metazoan transcription factors that are known to play a critical role in eye, ear, kidney and neural development. The mammalian Pax family of transcription factors is characterized by a ∼128-amino-acid DNA-binding paired domain that makes sequence-specific contacts with DNA. The diversity in Pax gene activities emerges from complex modes of interaction with enhancer regions and heterodimerization with multiple interaction partners. Based on in vitro optimal binding-site selection studies and enhancer identification assays, it has been suggested that Pax proteins may recognize and bind their target DNA elements with different binding modes/topologies, however this hypothesis has not yet been structurally explored. One of the most extensively studied DNA target elements of the Pax6 paired domain is the eye-lens specific DC5 (δ-crystallin) enhancer element. In order to shed light on Pax6-DC5 DNA interactions, the related paired-domain prototype Pax9 was crystallized with the minimal δ-crystallin DC5 enhancer element and preliminary X-ray diffraction analysis was attempted. A 3.0 Å resolution native data set was collected at the National Synchrotron Light Source (NSLS), Brookhaven from crystals grown in a solution consisting of 10%(w/v) PEG 20K, 20%(v/v) PEG 550 MME, 0.03 M NaNO3, 0.03 M Na2HPO4, 0.03 M NH2SO4, 0.1 M MES/imidazole pH 6.5. The data set was indexed and merged in space group C2221, with unit-cell parameters a = 75.74, b = 165.59, c = 70.14 Å, α = β = γ = 90°. The solvent content in the unit cell is consistent with the presence of one Pax9 paired domain bound to duplex DNA in the asymmetric unit.
authors.affiliation: Donnelly Centre for Biomolecular Research, University of Toronto, 160 College Street, Toronto, Ontario M5S 3E1, Canada.
authors.forename: Kamesh
authors.initials: K
authors.lastname: Narasimhan
authors.affiliation: Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore.
authors.forename: Antonia
authors.initials: A
authors.lastname: Hilbig
authors.affiliation: Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore.
authors.forename: Barath
authors.initials: B
authors.lastname: Udayasuryan
authors.affiliation: Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore.
authors.forename: Sriram
authors.initials: S
authors.lastname: Jayabal
authors.affiliation: Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore.
authors.forename: Prasanna R
authors.initials: PR
authors.lastname: Kolatkar
authors.affiliation: Genome Institute of Singapore, 60 Biopolis Street, Singapore 138672, Singapore.
authors.forename: Ralf
authors.initials: R
authors.lastname: Jauch
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003460:Crystallization; D018360:Crystallography, X-Ray; D004247:DNA / Q000737:chemistry; D004742:Enhancer Elements, Genetic; D051379:Mice; D008969:Molecular Sequence Data; D051764:PAX9 Transcription Factor; D051761:Paired Box Transcription Factors / Q000737:chemistry*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D038207:delta-Crystallins / Q000235:genetics
chemical_list: D051764:PAX9 Transcription Factor; D051761:Paired Box Transcription Factors; C488759:Pax9 protein, mouse; D038207:delta-Crystallins; D004247:DNA
keywords: Pax9; paired domain; δ-crystallin DC5 enhancer