Cell type-specific transcription during Bacillus sporulation is established by sigmaF. SpoIIAB is an anti-sigma that binds and negatively regulates sigmaF, as well as a serine kinase that phosphorylates and inactivates the anti-anti-sigma SpoIIAA. The crystal structure of sigmaF bound to the SpoIIAB dimer in the low-affinity, ADP form has been determined at 2.9 A resolution. SpoIIAB adopts the GHKL superfamily fold of ATPases and histidine kinases. A domain of sigmaF contacts both SpoIIAB monomers, while 80% of the sigma factor is disordered. The interaction occludes an RNA polymerase binding surface of sigmaF, explaining the SpoIIAB anti-sigma activity. The structure also explains the specificity of SpoIIAB for its target sigma factors and, in combination with genetic and biochemical data, provides insight into the mechanism of SpoIIAA anti-anti-sigma activity.
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http://dx.doi.org/10.1016/s0092-8674(02)00662-1 | DOI Listing |
J Nat Prod
January 2025
Department of Nephrology, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, People's Republic of China.
In the search for novel natural products with hepatoprotective effects against acetaminophen-induced acute liver injury, the marine-derived fungus WHUF0198 was investigated. Seventeen undescribed pyranopyridone alkaloids, aculeapyridones A-Q (-), were isolated by bioactivity-guided fractionation of an extract obtained by coculture of the WHUF0198 with the mangrove-associated fungus sp. DM27.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Key Laboratory of Ocean Observation‑Imaging Testbed of Zhejiang Province, Ocean College, Zhejiang University, Hangzhou, 310058, China.
Cherenkov radiation (CR) is a fascinating phenomenon that occurs not only in electromagnetic (EM) waves but also in water waves. The V-shaped wake formed by a moving object on the water surface results from the constructive interference of water waves of different wavelengths, similar to CR. We designed and fabricated a one-dimensional (1D) water wave crystal to analogize the behavior of moving particles in water waves.
View Article and Find Full Text PDFActa Crystallogr B Struct Sci Cryst Eng Mater
February 2025
Department of Chemical Engineering, Sargent Centre for Process Systems Engineering, Institute for Molecular Science and Engineering, Imperial College London, London SW7 2AZ, United Kingdom.
We present an approach to reduce this computational cost substantially, based on the partitioning of the molecule into geometrically separated torsional groups, with the dependence of the intramolecular energy and atomic point charges and dependent degrees of freedom on molecular conformation being computed as a linear combination of the contributions of these groups. This can lead to large savings in computational cost without a significant impact on accuracy, as demonstrated in the cases of N-acetyl-para-aminophenol (paracetamol) and methyl 4-hydroxybenzoate (methyl paraben). The approach is also applied successfully to two larger molecules, benzyl [4-(4-methyl-5-[(4-methylphenyl)sulfonyl]-1,3-thiazol-2-yl)phenyl]carbamate (molecule XX from the fifth CSP blind test) and (2S)-2-[4-(3-fluorobenzyloxy)benzylamino]propionamide (safinamide), for which we conduct the first reported CSP study.
View Article and Find Full Text PDFDalton Trans
January 2025
Institute of Inorganic Chemistry, Georg-August-Universität Göttingen, Göttingen Tammannstrasse 4, D-37077, Germany.
The reactions of LAlH (L = HC(CMeNAr), Ar = 2,6-PrCH) (1) with diphenylphosphane oxide [PhP(O)H], diphenylphosphinamide [PhP(O)NH], and diaryl/alkyl phosphane [(RO)P(O)H (R = Ph, or Pr)] afford their corresponding compounds with compositions LAl(H)OP(Ph) (2), LAl[OP(Ph)] (3), LAl{[N(H)P(O)(Ph)][OP(Ph)]} (4), LAl(OPr) (5), and LAl(OPh) (6), respectively. These reactions probably undergo a process of dehydrogenation coupling, deaminating dehydrogenation coupling, or chain-breaking coupling. It is noteworthy to mention that the reaction of compound 1 with 2 equiv.
View Article and Find Full Text PDFJ Nat Med
January 2025
Graduate School of Pharmaceutical Sciences, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8675, Japan.
A new diterpenoid, carneadiol (1), with an unprecedented tricyclic carbon skeleton, was isolated from the culture extracts of Nocardia carnea IFM 12324. The structure of compound 1 was elucidated using spectral studies, including various NMR data. The absolute configuration of 1 was determined using X-ray crystallographic analysis with the crystalline sponge method.
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