The specificity of protein-nucleic acid recognition is believed to originate largely from hydrogen bonding between protein polar atoms, primarily side-chain and polar atoms of nucleic acid bases. One way to design new nucleic acid binding proteins of novel specificity is by structure-guided alterations of the hydrogen bonding patterns of a nucleic acid-protein complex. We have used cI repressor...

Three heterocyclic dyes were synthesized having in mind the changes photovoltaic, optical and redox properties by functionalization of 5-aryl-thieno[3,2-b]thiophene, 5-arylthiophene bis-methylpyrrolylthiophene π-bridges with different donor, acceptor/anchoring groups. Knoevenagel condensation aldehyde precursors 2-cyanoacetic acid was used to prepare donor-acceptor functionalized molecules. The...

The spectral shift from 420 to 338 nm when pure bacterial D-amino acid transaminase binds D-amino acid substrates is also exhibited in part by high concentrations of L-amino acids (L-alanine and L-glutamate) but not by simple dicarboxylic acids or monoamines. Slow processing of L-alanine to D-alanine was observed both by coupled enzymatic assays using D-amino acid oxidase and by high pressure l...

The ability to molecularly engineer materials is a powerful tool toward increasingly performing heterogeneous catalysts. Porous organic polymers stand out as photocatalysts due their high chemical stability, outstanding optoelectronic properties and easy tunable syntheses. In photocatalysis, the insertion of photosensitizing π-extended molecules into well-defined donor-acceptor junctions suppos...

Aminoacyl-tRNA synthetases recognize tRNA anticodon and 3' acceptor stem bases. Synthetase Urzymes acylate cognate tRNAs even without anticodon-binding domains, in keeping with the possibility that acceptor stem recognition preceded anticodon recognition. Representing tRNA identity elements with two bits per base, we show that the anticodon encodes the hydrophobicity of each amino acid side-cha...

The ability of the water-soluble DD-carboxypeptidases of Streptomyces strains albus G, R61, Kll and R39 to perform transpeptidation was studied. The donor was diacetylL-lysyl-D-alanyl-D-alanine, and a whole range of amino acids, peptides and structurally related amino compounds were tested for acceptor function. No compound tested was an acceptor for the enzyme from strain albus G whereas the e...

The specific formylation of initiator methionyl-tRNA by methionyl-tRNA formyltransferase (MTF; EC 2.1.2.9) is important for the initiation of protein synthesis in eubacteria and in eukaryotic organelles. The determinants for formylation in the tRNA are clustered mostly in the acceptor stem. As part of studies on the molecular mechanism of recognition of the initiator tRNA by MTF, we report here...

The mechanism of fumarate reduction in Geobacter sulfurreducens was investigated. The genome contained genes encoding a heterotrimeric fumarate reductase, FrdCAB, with homology to the fumarate reductase of Wolinella succinogenes and the succinate dehydrogenase of Bacillus subtilis. Mutation of the putative catalytic subunit of the enzyme resulted in a strain that lacked fumarate reductase activ...

A spectrophotometric study concerning the interaction between Trimethoprim (TMP) ,Sulfamethoxazole (SFMx), as n-donor and 2,3-dichloro-5,6- dicyano-P-benzoquinine (DDQ) and chloranilic acid (CA) as π-acceptor were been performed at 25°C. The results of interaction of CA and DDQwith TMP indicate the formation of a 1:1, 1:2, charge transfer complexes through non equilibrium reactions. In the case...

An azo dye used as photosensitizers in Dye-sensitized solar cells DSSCs. Azo dyes economically superior to organometallic dyes because they are color variation and cheap. The spectrophotometric evaluation of an azo dye in solution and on a TiO2 substrate show that the dye form J-aggregation on the nanostructured TiO2 substrate. Oxidation potential measurements for used azo dyes ensured an energ...