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1sq9
From Proteopedia
Structure of Ski8p, a WD repeat protein involved in mRNA degradation and meiotic recombination
Structural highlights
Function[SKI8_YEAST] Involved in double-strand break (DSB) formation during meiotic recombination through stabilization of SPO11 association with meiotic chromosome and helping SPO11 to recruit other DSB proteins like REC102 and REC104 to meiotic chromosomes. Also component of the SKI complex involved in 3'-mRNA degradation pathway. Represses dsRNA virus propagation by specifically blocking translation of viral mRNAs, perhaps recognizing the absence of CAP or poly(A). Essential for controlling the propagation of M double-stranded RNA (dsRNA) and thus for preventing virus-induced cytopathology.[1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] 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 PubMedSki8p is a 44-kD protein that primarily functions in the regulation of exosome-mediated, 3'--> 5' degradation of damaged mRNA. It does so by forming a complex with two partner proteins, Ski2p and Ski3p, which complete a complex that is capable of recruiting and activating the exosome/Ski7p complex that functions in RNA degradation. Ski8p also functions in meiotic recombination in complex with Spo11 in yeast. It is one of the many hundreds of primarily eukaryotic proteins containing tandem copies of WD repeats (also known as WD40 or beta-transducin repeats), which are short ~40 amino acid motifs, often terminating in a Trp-Asp dipeptide. Genomic analyses have demonstrated that WD repeats are found in 1%-2% of proteins in a typical eukaryote, but are extremely rare in prokaryotes. Almost all structurally characterized WD-repeat proteins are composed of seven such repeats and fold into seven-bladed beta propellers. Ski8p was thought to contain five WD repeats on the basis of primary sequence analysis implying a five-bladed propeller. The 1.9 A crystal structure unexpectedly exhibits a seven-bladed propeller fold with seven structurally authentic WD repeats. Structure-based sequence alignments show additional sequence diversity in the two undetected repeats. This demonstrates that many WD repeats have not yet been identified in sequences and also raises the possibility that the seven-bladed propeller may be the predominant fold for this family of proteins. The structure of Ski8p, a protein regulating mRNA degradation: Implications for WD protein structure.,Madrona AY, Wilson DK Protein Sci. 2004 Jun;13(6):1557-65. PMID:15152089[13] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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