RESUMEN
The crystal structure of a hypothetical protein MJ0366, derived from Methanocaldococcus jannaschii was solved at 1.9 Å resolution using synchrotron radiation. MJ0366 was crystallized as a monomer and has knot structural arrangement. Intriguingly, the solved structure consists of novel 'KNOT' fold conformation. The 31 trefoil knot was observed in the structure. The N-terminal and C-terminal ends did not participate in knot formation.
Asunto(s)
Proteínas Bacterianas/química , Proteínas Bacterianas/ultraestructura , Methanocaldococcus/metabolismo , Modelos Químicos , Modelos Moleculares , Simulación por Computador , Cristalografía , Conformación Proteica , Pliegue de ProteínaRESUMEN
RNA binding proteins control gene expression by the attenuation/antitermination mechanism. HutP is an RNA binding antitermination protein. It regulates the expression of hut operon when it binds with RNA by modulating the secondary structure of single-stranded hut mRNA. HutP necessitates the presence of l-histidine and divalent metal ion to bind with RNA. Herein, we report the crystal structures of ternary complex (HutP-l-histidine-Mg(2+)) and EDTA (0.5 M) treated ternary complex (HutP-l-histidine-Mg(2+)), solved at 1.9 Å and 2.5 Å resolutions, respectively, from Geobacillus thermodenitrificans. The addition of 0.5 M EDTA does not affect the overall metal-ion mediated ternary complex structure and however, the metal ions at the non-specific binding sites are chelated, as evidenced from the results of structural features.
Asunto(s)
Proteínas Bacterianas/química , Geobacillus/química , Proteínas de Unión al ARN/química , Proteínas Bacterianas/metabolismo , Sitios de Unión , Cristalografía por Rayos X , Geobacillus/metabolismo , Histidina/química , Histidina/metabolismo , Magnesio/química , Magnesio/metabolismo , Modelos Moleculares , Conformación Proteica , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismoRESUMEN
Ferritin is an iron regulatory protein. It is responsible for storage and detoxification of excess iron thereby it regulates iron level in the body. Here we report the crystal structure of ferritin with two endogenously expressed Fe atoms binding in both the sites. The protein was purified and characterized by MALDI-TOF and N-terminal amino acid sequencing. The crystal belongs to I4 space group and it diffracted up to 2.5Å. The structural analysis suggested that it crystallizes as hexamer and confirmed that it happened to be the first report of endogenously expressed Fe ions incorporated in both the A and B sites, situated in between the helices.
Asunto(s)
Escherichia coli/metabolismo , Compuestos Férricos/metabolismo , Ferritinas/metabolismo , Secuencia de Aminoácidos , Cristalografía por Rayos X , Escherichia coli/química , Ferritinas/química , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
In the title compound, [CoCl(CH5N)(C3H10N2)2]Cl2·H2O, the Co(III) ion has an octa-hedral coordination environment and is surrounded by four N atoms of two propane-1,3-diamine ligands in the equatorial plane, with another N atom of the methylamine ligand and a Cl atom occupying the axial positions. The crystal packing is stabilized by inter-molecular N-Hâ¯O, N-Hâ¯Cl, and O-Hâ¯Cl inter-actions, generating a three-dimensional network.