Dinucleotides complex

Using the principles outlined in this article, the crystal structures of the following complexes of RNase A have been determined the free enzyme, both with and without a sulfate ion in the active site, the enzyme-dinucleotide complex, the enzyme-cyclic phosphate intermediate complex, the enzyme-transition state complex, and the enzyme-product complex, all at or near atomic resolution. This structural informa-... 

Figure 16-31 (A) Structure of molybdopterin cytosine dinucleotide complexed with an atom of molybdenum. (B) Stereoscopic ribbon drawing of the structure of one subunit of the xanthine oxidase-related aldehyde oxidoreductase from Desulfo-vibrio gigas. Each 907-residue subunit of the homodimeric protein contains two Fe2S2 clusters visible at the top and the molybdenum-molybdopterin coenzyme buried in the center. (C) Alpha-carbon plot of portions of the protein surrounding the molybdenum-molybdopterin cytosine dinucleotide and (at the top) the two plant-ferredoxin-like Fe2S2 clusters. Each of these is held by a separate structural domain of the protein. Two additional domains bind the molybdopterin coenzyme and there is also an intermediate connecting domain. In xanthine oxidase the latter presumably has the FAD binding site which is lacking in the D. gigas enzyme. From Romao et al.633 Courtesy of R. Huber.

Complex I, see under Nicotinamide adenine dinucleotide Complex I-III properties of, 197 Complex II, see also Succinate dehydrogenase... 

Over the last few years, significant advances in the depth of understanding of the conformational features of the polynucleotide—platinum complex interaction have come from both solution (CD, NMR) and solid-state (X-Ray) studies on oligonucleotide fragments, particularly dinucleotide complexes. Excellent summaries of the status of model studies and their relationship to the molecular mechanism of cisplatin can be found in references [82 and 141]. These complement the earlier reviews [83, 84]. The features outlined do in fact confirm some of those expected from model studies, although there has not been an extensive comparison with the trans-isomcr. 

This result corresponds to 88.5 3.2% for Cd(dGMP)c]/N7- This stabihty enhancement for the Cd(dGMP) complex is by 0.27 0.15 log unit smaller than the one obtained for Cd[d(pGpG)] indicating that in the dinucleotide complex both guanine residues (Figure 16) are involved to some extent. 

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