1v66
Solution structure of human p53 binding domain of PIAS-1
Structural highlights
FunctionPIAS1_HUMAN Functions as an E3-type small ubiquitin-like modifier (SUMO) ligase, stabilizing the interaction between UBE2I and the substrate, and as a SUMO-tethering factor. Plays a crucial role as a transcriptional coregulation in various cellular pathways, including the STAT pathway, the p53 pathway and the steroid hormone signaling pathway. In vitro, binds A/T-rich DNA. The effects of this transcriptional coregulation, transactivation or silencing, may vary depending upon the biological context. Together with PRMT1, may repress STAT1 transcriptional activity, in the late phase of interferon gamma (IFN-gamma) signaling.[1] [2] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedA member of the PIAS (protein inhibitor of activated STAT) family of proteins, PIAS1, have been reported to serve as an E3-type SUMO ligase for tumor suppressor p53 and its own. It also was proposed that the N-terminal domain of PIAS1 interacts with DNA as well as p53. Extensive biochemical studies have been devoted recently to understand sumoylations and its biological implications, whereas the structural aspects of the PIAS family and the mechanism of its interactions with various factors are less well known to date. In this study, the three-dimensional structure of the N-terminal domain (residues 1-65) of SUMO ligase PIAS1 was determined by NMR spectroscopy. The structure revealed a unique four-helix bundle with a topology of an up-down-extended loop-down-up, a part of which the helix-extended loop-helix represented the SAP (SAF-A/B, Acinus, and PIAS) motif. Thus, this N-terminal domain may be referred to as a four-helix SAP domain. The glutathione S-transferase pull-down assay demonstrated that this domain possesses a binding ability to tumor suppressor p53, a target protein for sumoylation by PIAS1, whereas gel mobility assays showed that it has a strong affinity toward A/T-rich DNA. An NMR analysis of the four-helix SAP domain complexed with the 16-bp-long DNA demonstrated that one end of the four-helix bundle is the binding site and may fit into the minor groove of DNA. The three-dimensional structure and its binding duality are discussed in conjunction with the biological functions of PIAS1 as a SUMO ligase. NMR structure of the N-terminal domain of SUMO ligase PIAS1 and its interaction with tumor suppressor p53 and A/T-rich DNA oligomers.,Okubo S, Hara F, Tsuchida Y, Shimotakahara S, Suzuki S, Hatanaka H, Yokoyama S, Tanaka H, Yasuda H, Shindo H J Biol Chem. 2004 Jul 23;279(30):31455-61. Epub 2004 May 8. PMID:15133049[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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