3u1m
Structure of the mRNA splicing complex component Cwc2
Structural highlights
FunctionCWC2_YEAST Involved in the first step of pre-mRNA splicing. Required for cell growth and cell cycle control. Plays a role in the levels of the U1, U4, U5 and U6 snRNAs and the maintenance of the U4/U6 snRNA complex. May provide the link between the "nineteen complex" NTC spliceosome protein complex and the spliceosome through the U6 snRNA. Associates predominantly with U6 snRNAs in assembled active spliceosomes. Binds directly to the internal stem-loop (ISL) domain of the U6 snRNA and to the pre-mRNA intron near the 5' splice site during the activation and catalytic phases of the spliceosome cycle. Binds also to U1, U4, U5 and U6 snRNAs and to pre-mRNAs, in vitro. Is not required for the Prp2-mediated remodeling of the activated spliceosome.[1] [2] Publication Abstract from PubMedThe Prp19-associated complex [NTC (nineteen complex)] plays a crucial role in intron removal during premature mRNA splicing in eukaryotes. Only one component of the NTC, Cwc2, is capable of binding RNA. In the present study we report the 1.9 A (1 A=0.1 nm) X-ray structure of the Cwc2 core domain, which is both necessary and sufficient for RNA binding. The Cwc2 core domain contains two sub-domains, a CCCH-type ZnF (zinc finger) and a RRM (RNA recognition motif). Unexpectedly, the ZnF domain and the RRM form a single folding unit, glued together by extensive hydrophobic interactions and hydrogen bonds. Structure-guided mutational analysis revealed that the intervening loop [known as the RB loop (RNA-binding loop)] between ZnF and RRM plays an essential role in RNA binding. In addition, a number of highly conserved positively charged residues on the beta-strands of RRM make an important contribution to RNA binding. Intriguingly, these residues and a portion of the RB loop constitute an extended basic surface strip that encircles Cwc2 halfway. The present study serves as a framework for understanding the regulatory function of the NTC in RNA splicing. Structure of the mRNA splicing complex component Cwc2: insights into RNA recognition.,Lu P, Lu G, Yan C, Wang L, Li W, Yin P Biochem J. 2012 Jan 15;441(2):591-7. doi: 10.1042/BJ20111385. PMID:21957909[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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