gRNA/pre-mRNA annealing and RNA chaperone activities of RBP16

Editing in trypanosomes involves the addition or deletion of uridines at specific sites to produce translatable mitochondrial mRNAs. RBP16 is an accessory factor from Trypanosoma brucei that affects mitochondrial RNA editing in vivo and also stimulates editing in vitro. We report here experiments aimed at elucidating the biochemical activities of RBP16 involved in modulating RNA editing. In vitro RNA annealing assays demonstrate that RBP16 significantly stimulates the annealing of gRNAs to cognate pre-mRNAs. In addition, RBP16 also facilitates hybridization of partially complementary RNAs unrelated to the editing process. The RNA annealing activity of RBP16 is independent of its high-affinity binding to gRNA oligo(U) tails, consistent with the previously reported in vitro editing stimulatory properties of the protein. In vivo studies expressing recombinant RBP16 in mutant Escherichia coli strains demonstrate that RBP16 is an RNA chaperone and that in addition to RNA annealing activity, it contains RNA unwinding activity. Our data suggest that the mechanism by which RBP16 facilitates RNA editing involves its capacity to modulate RNA secondary structure and promote gRNA/pre-mRNA annealing.     

植物冷激蛋白的研究进展

冷激蛋白是存在于细菌、植物与动物中的一类高度保守的核酸结合蛋白,其通过RNA分子伴侣活性参与转录、翻译及生长发育和逆境胁迫应答等细胞生理活动。本文主要从植物冷激蛋白的结构、表达模式、生物学功能以及应用前景等几个方面介绍了植物冷激蛋白的研究进展。     

1H, 13C and 15N resonance assignments of Ca2+ bound collagen-binding domain derived from a clostridial collagenase

¹H, ¹⁵N, and ¹³C NMR assignments for 116 amino acids (Gly893-Lys1008) of a bacterial collagen-binding domain (CBD) derived from Clostridium histolyticum class I collagenase were accomplished. Clostridial collagenases hydrolyze insoluble collagen. One to three copies of collagen-binding domains (CBDs) are present at their C-termini, each of which is the minimal segment required for the binding to the insoluble substrate. CBD has been shown to be able to anchor fused growth factors for up to 10 days in vivo. Structural analysis of the small domain with the unique function provides insights into designing a novel drug delivery vehicle by the rational drug design.     

Y-box结合蛋白功能及对肿瘤发生的影响

Y-box结合蛋白家族成员是一类高度保守的顺式作用元件, 广泛存在于原核及真核生物细胞中。它是一种多功能蛋白, 与转录调节、翻译调控、mRNA选择性剪接、DNA的修复、细胞增殖和再生等有关。Y-box结合蛋白的氨基酸序列包含3个结构域: 氨基酸N末端, 亲水结构域C末端, 冷休克结构域(cold shock domain CSD), 保守的冷休克结构域决定了Y-box结合蛋白的大部分功能。最近研究发现, 定位于细胞核中的YB-1蛋白在局部晚期非小细胞肺癌的预防上可作为新的靶位点, YB-1蛋白还可通过对抑癌基因p53启动子抑制起负调控作用, 此外, YB-1蛋白在PI3K/Akt信号通路中也起到重要的作用, 这些研究都为肿瘤的治疗提供了新的线索和启示。文章就Y-box结合蛋白功能及其对肿瘤发生的影响等方面进行概述。     

Sequence-specific 1H, 13C, and 15N resonance assignments of GRP1 PH domain

The carboxy-terminal pleckstrin homology (PH) domain recruits GRP1 to the plasma membrane through the specific binding to phosphatidylinositol 3,4,5-trisphosphate [PtdIns(3,4,5)P₃]. Here, we describe backbone and side chain assignments of the GRP1 PH domain determined by triple resonance experiments. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

IBIS--a tool for automated sequential assignment of protein spectra from triple resonance experiments

We have developed a tool for computer-assisted assignments of protein NMR spectra from triple resonance data. The program is designed to resemble established manual assignment procedures as closely as possible. IBIS exports its results in XEASY format. Thus, using IBIS the operator has continuous visual and accounting control over the progress of the assignment procedure. IBIS achieves complete assignments for those residues that exhibit sequential triple resonance connectivities within a few hours or days.     

Structure prediction and docking-based molecular insights of human YB-1 and nucleic acid interaction

Y-box-binding protein 1 (YB-1), a cold shock domain protein, is one of the most conserved nucleic acid-binding proteins. The multifunctional human YB-1 is a member of a large family of proteins with an evolutionary ancient cold shock domain. The presence of a cold shock domain is a specific feature of Y-box-binding proteins and allows attributing them to a wider group of proteins containing a cold shock domain. This protein is involved in a number of cellular processes including proliferation, differentiation and stress response. The YB-1 performs its function both in the cytoplasm and in the cell nucleus. In this study, we present the structure of full-length human YB-1 protein along with investigation of their nucleic acid-binding preferential. The study also focuses on biases for particular purine and pyrimidine bases. The overall goal of this study was to model and validate full-length YB-1 protein and to compare its nucleic acid-binding studies with previous reports.