6pun
From Proteopedia
Crystal structure of a ternary complex of FBF-2 with LST-1 (site B) and compact FBE RNA
Structural highlights
FunctionFBF2_CAEEL Involved in the control of stem cells and sex determination in the C.elegans hermaphrodite germline. May also play a role in the hermaphrodite germline proliferation and oogenesis. Binds specifically to the regulatory region of fem-3 3'-UTR and mediates the sperm/oocyte switch. Negatively regulates gld-3 expression possibly by directly binding to two sites within the gld-3 isoform B 3'-UTR.[1] [2] Publication Abstract from PubMedIn the Caenorhabditis elegans germline, fem-3 Binding Factor (FBF) partners with LST-1 to maintain stem cells. A crystal structure of an FBF-2/LST-1/RNA complex revealed that FBF-2 recognizes a short RNA motif different from the characteristic 9-nt FBF binding element, and compact motif recognition coincided with curvature changes in the FBF-2 scaffold. Previously, we engineered FBF-2 to favor recognition of shorter RNA motifs without curvature change (Bhat et al., 2019). In vitro selection of RNAs bound by FBF-2 suggested sequence specificity in the central region of the compact element. This bias, reflected in the crystal structure, was validated in RNA-binding assays. FBF-2 has the intrinsic ability to bind to this shorter motif. LST-1 weakens FBF-2 binding affinity for short and long motifs, which may increase target selectivity. Our findings highlight the role of FBF scaffold flexibility in RNA recognition and suggest a new mechanism by which protein partners refine target site selection. A crystal structure of a collaborative RNA regulatory complex reveals mechanisms to refine target specificity.,Qiu C, Bhat VD, Rajeev S, Zhang C, Lasley AE, Wine RN, Campbell ZT, Hall TMT Elife. 2019 Aug 9;8. pii: 48968. doi: 10.7554/eLife.48968. PMID:31397673[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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