Crystallization and preliminary X‐ray diffraction analysis of the Pax9 paired domain bound to a DC5 enhancer DNA element. Issue 10 (1st October 2014)

• Record Type: Journal Article
• Authors: Narasimhan, Kamesh; Hilbig, Antonia; Udayasuryan, Barath; Jayabal, Sriram; Kolatkar, Prasanna R.; Jauch, Ralf
• Is Part Of: Acta crystallographica. Volume 70:Issue 10(2014:Oct.)
• Page Start: 1357
• Page End: 1361
• Publication Date: 2014-10-01
• Subjects: Crystallography -- Periodicals; Crystals -- Periodicals; 548
• DOI: 10.1107/S2053230X14017415
• Languages: English
• ISSNs: 2053-230X

Abstract

<abstract abstract-type="main" xml:lang="en"> <title> <x xml:space="preserve">Abstract</x> </title> <p>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 <italic>in vitro</italic> 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%(<italic>w</italic>/<italic>v</italic>) PEG 20K, 20%(<italic>v</italic>/<italic>v</italic>) PEG 550 MME, 0.03 <italic>M</italic> NaNO<sub>3</sub>, 0.03 <italic>M</italic> Na<sub>2</sub>HPO<sub>4</sub>, 0.03 <italic>M</italic> NH<sub>2</sub>SO<sub>4</sub>, 0.1 <italic>M</italic> MES/imidazole pH 6.5. The data set was indexed and merged in space group <italic>C</italic>222<sub>1</sub>, with unit‐cell parameters <italic>a</italic> = 75.74, <italic>b</italic> = 165.59, <italic>c</italic> = 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.</p> </abstract>