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Crystal Structure and RNA Binding of the Tex Protein from Pseudomonas aeruginosa
Author(s) -
Close Devin,
Johnson Sean J,
Hill Christopher P
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.2_supplement.205
Subject(s) - nucleic acid , rna , transcription (linguistics) , scaffold protein , biology , binding site , rna binding protein , protein structure , rna polymerase , microbiology and biotechnology , chemistry , biochemistry , gene , philosophy , linguistics , signal transduction
Tex is a highly conserved bacterial protein that likely functions in a variety of transcriptional processes. Here we describe two crystal structures of the 86 kDa Tex protein from Pseudomonas aeruginosa at 2.3 Å and 2.5 Å resolution, respectively. These structures reveal a relatively flat and elongated protein, with several potential nucleic‐acid binding motifs clustered at one end, including an S1 domain near the C‐terminus that displays considerable structural flexibility. Tex binds nucleic acids, with a preference for ssRNA, and the Tex S1 domain is required for this binding activity. Point mutants further demonstrate that the primary nucleic acid binding site corresponds to a surface of the S1 domain. Sequence alignment and modeling indicate that the eukaryotic Spt6 transcription factor adopts a similar core structure. Structural analysis further suggests that the RNA polymerase and nucleosome interacting regions of Spt6 flank opposite sides of the Tex‐like scaffold. Therefore, the Tex structure may represent a conserved scaffold that binds ssRNA to regulate transcription in both eukaryotic and prokaryotic organisms.