3pla
From Proteopedia
Crystal structure of a catalytically active substrate-bound box C/D RNP from Sulfolobus solfataricus
Structural highlights
Function[FLPA_SULSO] Involved in pre-rRNA and tRNA processing. Utilizes the methyl donor S-adenosyl-L-methionine to catalyze the site-specific 2'-hydroxyl methylation of ribose moieties in rRNA and tRNA. Site specificity is provided by a guide RNA that base pairs with the substrate. Methylation occurs at a characteristic distance from the sequence involved in base pairing with the guide RNA.[1] [2] [D0KRE2_SULS9] Multifunctional RNA-binding protein that recognizes the K-turn motif in ribosomal RNA, the RNA component of RNase P, box H/ACA, box C/D and box C'/D' sRNAs.[HAMAP-Rule:MF_00326] Publication Abstract from PubMedBox C/D RNA protein complexes (RNPs) direct site-specific 2'-O-methylation of RNA and ribosome assembly. The guide RNA in C/D RNP forms base pairs with complementary substrates and selects the modification site using a molecular ruler. Despite many studies of C/D RNP structure, the fundamental questions of how C/D RNAs assemble into RNPs and how they guide modification remain unresolved. Here we report the crystal structure of an entire catalytically active archaeal C/D RNP consisting of a bipartite C/D RNA associated with two substrates and two copies each of Nop5, L7Ae and fibrillarin at 3.15-A resolution. The substrate pairs with the second through the eleventh nucleotide of the 12-nucleotide guide, and the resultant duplex is bracketed in a channel with flexible ends. The methyltransferase fibrillarin binds to an undistorted A-form structure of the guide-substrate duplex and specifically loads the target ribose into the active site. Because interaction with the RNA duplex alone does not determine the site specificity, fibrillarin is further positioned by non-specific and specific protein interactions. Compared with the structure of the inactive C/D RNP, extensive domain movements are induced by substrate loading. Our results reveal the organization of a monomeric C/D RNP and the mechanism underlying its site-specific methylation activity. Structural basis for site-specific ribose methylation by box C/D RNA protein complexes.,Lin J, Lai S, Jia R, Xu A, Zhang L, Lu J, Ye K Nature. 2011 Jan 27;469(7331):559-563. PMID:21270896[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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Categories: Saccharolobus solfataricus | Large Structures | Suls9 | Jia, R | Lai, S | Lin, J | Lu, J | Xu, A | Ye, K | Zhang, L | Box c/d rna | Guide rna | Methyltransferase | Rna-binding | Rna-protein complex | Sam | Transferase-rna complex
