Bis(ferrocene­carboxyl­ato-κO)bis­(2-pyridyl­methanol-κ2 N,O)cobalt(II)

The title complex mol­ecule, [Fe2Co(C5H5)2(C6H4O2)2(C6H7NO)2], has a crystallographic imposed centre of symmetry. The CoII atom displays a distorted octa­hedral coordination geometry, provided by the O atoms of two monodentate ferrocene­carboxyl­ate anions and by the N and O atoms of two 2-pyridyl­methanol mol­ecule. The mol­ecular conformation is stabilized by intra­molecular C—H⋯O hydrogen bonds

Poly[μ4-succinato-μ2-succinato-bis[diamminecopper(II)]]

In the title compound, [Cu(C4H4O4)(NH3)2]n, the Cu atom is coordinated by the N atoms of two ammonia mol­ecules and four O atoms from three different succinate ligands in a highly distorted octa­hedral geometry. The Cu atom and the C and O atoms of the succinate ligands lie on a mirror plane. Two adjacent CuO4N2 octa­hedra share one common O–O edge, forming a Cu2O6N4 biocta­hedron with a Cu⋯Cu separation of 3.524 (2) Å. Neighboring biocta­hedra are connected by bis-unidentate succinate anions in the a-axis direction, while in the c-axis direction biocta­hedra are connected by bis-bidentate succinate anions, leading to an infinite two-dimensional network structure. These networks are further connected along the a-axis direction by hydrogen bonds between ammonia ligands and carboxyl­ate O atoms of neighboring network layers, forming a three-dimensional lamellar structure

Triphenyl­bis[4-(trifluoro­meth­yl)benzoato-κO]anti­mony(V)

The title complex, [Sb(C6H5)3(C8H4F3O2)2], is located on a twofold axis defined by the metal center and two C atoms of a coordinated phenyl group. The environment of the Sb atom approximates a trigonal-bipyramidal geometry, with the axial positions occupied by the O atoms of symmetry-related 4-(trifluoro­meth­yl)benzoate ligands. In this ligand, the CF3 group is disordered by rotation about the C—C bond and the F atoms are distributed over two sets of sites with occupancies of 0.62 (3) and 0.38 (3). In the crystal, mol­ecules are assembled in a three-dimensional framework through weak C—H⋯O hydrogen bonds

Evolutionary transition between invertebrates and vertebrates via methylation reprogramming in embryogenesis

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Xu, X., Li, G., Li, C., Zhang, J., Wang, Q., Simmons, D. K., Chen, X., Wijesena, N., Zhu, W., Wang, Z., Wang, Z., Ju, B., Ci, W., Lu, X., Yu, D., Wang, Q., Aluru, N., Oliveri, P., Zhang, Y. E., Martindale, M. Q., & Liu, J. Evolutionary transition between invertebrates and vertebrates via methylation reprogramming in embryogenesis. National Science Review, 6(5), (2019):993-1003, doi:10.1093/nsr/nwz064.Major evolutionary transitions are enigmas, and the most notable enigma is between invertebrates and vertebrates, with numerous spectacular innovations. To search for the molecular connections involved, we asked whether global epigenetic changes may offer a clue by surveying the inheritance and reprogramming of parental DNA methylation across metazoans. We focused on gametes and early embryos, where the methylomes are known to evolve divergently between fish and mammals. Here, we find that methylome reprogramming during embryogenesis occurs neither in pre-bilaterians such as cnidarians nor in protostomes such as insects, but clearly presents in deuterostomes such as echinoderms and invertebrate chordates, and then becomes more evident in vertebrates. Functional association analysis suggests that DNA methylation reprogramming is associated with development, reproduction and adaptive immunity for vertebrates, but not for invertebrates. Interestingly, the single HOX cluster of invertebrates maintains unmethylated status in all stages examined. In contrast, the multiple HOX clusters show dramatic dynamics of DNA methylation during vertebrate embryogenesis. Notably, the methylation dynamics of HOX clusters are associated with their spatiotemporal expression in mammals. Our study reveals that DNA methylation reprogramming has evolved dramatically during animal evolution, especially after the evolutionary transitions from invertebrates to vertebrates, and then to mammals.This work was supported by the National Key Research and Development Program of China (2018YFC1003303), the Strategic Priority Research Program of the CAS (XDB13040200), the National Natural Science Foundation of China (91519306, 31425015), the Youth Innovation Promotion Association of the CAS and the Key Research Program of Frontier Sciences, CAS (QYZDY-SSW-SMC016)

Approaches and Vectors for Efficient Cochlear Gene Transfer in Adult Mouse Models

Inner ear gene therapy using adeno-associated viral vectors (AAVs) in neonatal mice can alleviate hearing loss in mouse models of deafness. However, efficient and safe transgene delivery to the adult mouse cochlea is critical for the effectiveness of AAV-mediated therapy. Here, we examined three gene delivery approaches including posterior semicircular canal (PSCC) canalostomy, round window membrane (RWM) injection, and tubing-RWM+PSCC (t-RP) in adult mice. Transduction rates and survival rates of cochlear hair cells were analyzed, hearing function was recorded, AAV distribution in the sagittal brain sections was evaluated, and cochlear histopathologic images were appraised. We found that an injection volume of 1 μL AAV through the PSCC is safe and highly efficient and does not impair hearing function in adult mice, but local injection allows AAV vectors to spread slightly into the brain. We then tested five AAV serotypes (PHP.eB, IE, Anc80L65, AAV2, and PHP.s) in parallel and observed the most robust eGFP expression in inner hair cells, outer hair cells, and spiral ganglion neurons throughout the cochlea after AAV-Anc80L65 injection. Thus, PSCC-injected Anc80L65 provides a foundation for gene therapy in the adult cochlea and will facilitate the development of inner ear gene therapy

Cation-π interactions: Synthesis and crystal structure of complex [K(DB18C6)]I₃

1202-1204A dibenzo-18-crown-6 (DB18C6) complex, [K(DB18C6)]I3 has been isolated and characterized by elemental analysis, IR and X-ray diffraction analysis. The complex belongs to triclinic, space group P21/c with cell dimensions, a = 0.97870(17), b = 1.6909(3), c = 1.5435(3) nm, β= 98.435(3)·, V = 2.5266(7) nm3, Z = 2, Dcalc. = 1.026 Mg/m3, F(000) = 740, RI = 0.0534 and wR2 = 0.1666. In the solid state, two [K(DB18C6)]+ complex cations form a dimeric structure bridged by K+-π interactions

Structural mechanism for nucleotide-driven remodeling of the AAA-ATPase unfoldase in the activated human 26S proteasome

The proteasome is a sophisticated ATP-dependent molecular machine responsible for protein degradation in all known eukaryotic cells. It remains elusive how conformational changes of the AAA-ATPase unfoldase in the regulatory particle (RP) control the gating of the substrate–translocation channel leading to the proteolytic chamber of the core particle (CP). Here we report three alternative states of the ATP-γ-S-bound human proteasome, in which the CP gates are asymmetrically open, visualized by cryo-EM at near-atomic resolutions. At least four nucleotides are bound to the AAA-ATPase ring in these open-gate states. Variation in nucleotide binding gives rise to an axial movement of the pore loops narrowing the substrate-translation channel, which exhibit remarkable structural transitions between the spiral-staircase and saddle-shaped-circle topologies. Gate opening in the CP is thus regulated by nucleotide-driven conformational changes of the AAA-ATPase unfoldase. These findings demonstrate an elegant mechanism of allosteric coordination among sub-machines within the human proteasome holoenzyme

One-dimensional chain crown ether complexes: Synthesis and crystal structure of [Na(18-crown-6)]₂[M(mnt)₂](M = Zn, Cd)

327-330The reactions of IR-crown-6 with Na2[Zn(mnt)2] and Na2[Cd(mnt)2] have been studied and the complexes [Na(18-crown-6)]2[M(mnt)2](M = Zn, Cd), are characterized by elemental analysis, IR spectrum and X-ray diffraction analysis. 1 and 2 belong to monoclinic, space group c2/c with cell dimensions, 1: a = 2.2418(6), b = 1.1359(3), c = 1.9887(6) nm, β= 120.391 (4)o, V = 4.368(2), nm3, Z = 4, Dcalcd = 1.399 Mg/m3, F(000) = 1920, R1 = 0.0302, wR2 = 0.0560 and 2: a = 2.2547(6), b = 1.1412(3), c = 1.9938(6) nm, β=119.715(4)°, V = 4.455 nm3, Z = 4, Dcalcd = 1.442 Mg/m3 , F(000)= 1992, R1 = 0.0384, wR2 = 0.0575. Two complexes display a one-dimensional chain of [Na(18C6)]+(complex cations and [M(mnt)2]2- (M = Zn, Cd) complex anion bridged by Na-O interactions between adjacent  [Na(18C6)]+ units respectively