3nfq
Crystal structure of the conserved central domain of yeast Spn1/Iws1
Structural highlights
FunctionIWS1_YEAST Transcription factor involved in RNA polymerase II transcription regulation. May function in both SPT15/TBP post-recruitment and recruitment steps of transcription.[1] [2] Publication Abstract from PubMedSpn1 plays essential roles in the regulation of gene expression by RNA polymerase II (RNAPII), and it is highly conserved in organisms ranging from yeast to humans. Spn1 physically and/or genetically interacts with RNAPII, TBP (TATA-binding protein), TFIIS (transcription factor IIS), and a number of chromatin remodeling factors (Swi-Snf and Spt6). The central domain of Spn1 (residues 141-305 out of 410) is necessary and sufficient for performing the essential functions of SPN1 in yeast cells. Here, we report the high-resolution (1.85 A) crystal structure of the conserved central domain of Saccharomyces cerevisiae Spn1. The central domain is composed of eight alpha-helices in a right-handed superhelical arrangement and exhibits structural similarity to domain I of TFIIS. A unique structural feature of Spn1 is a highly conserved loop, which defines one side of a pronounced cavity. The loop and the other residues forming the cavity are highly conserved at the amino acid level among all Spn1 family members, suggesting that this is a signature motif for Spn1 orthologs. The locations and the molecular characterization of temperature-sensitive mutations in Spn1 indicate that the cavity is a key attribute of Spn1 that is critical for its regulatory functions during RNAPII-mediated transcriptional activity. The Transcription Factor Spn1 Regulates Gene Expression via a Highly Conserved Novel Structural Motif.,Pujari V, Radebaugh CA, Chodaparambil JV, Muthurajan UM, Almeida AR, Fischbeck JA, Luger K, Stargell LA J Mol Biol. 2010 Sep 25. PMID:20875428[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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