Five crystal structures

We report the crystal structures of four chlorinated dioxins—the 2,7-dichloro-, 2,8-dichloro-, 2,3,7,8-tetrachloro-, and octachlorodibenzo-p-dioxins. Thus, five crystal structures of chlorodioxins are now known. 

S H Liaw, D Eisenberg (1994) Structural model for the reaction mechanism of glutamine synthetase, based on five crystal structures of enzyme-substtate complexes, Biochemistry 33(3) 675—681... 

Three of the five crystal structures of eukaryotic MCOs archived in the PDB are of laccases from Coprinus cinereus... 

Prediction 2 In the static state the most hydrophobic side of the rotor faces the least polar side of the motor housing. Examination of five crystal structures with different... 

Five crystal structures involving thallium have been described, three of which involve oxide systems. In TlgO, which can be described as a distorted an/Z-Cdlg structure, the n+ ion has three oxygen near-neighbours at distances from 2.52 to 2.56 A, with further oxygen atoms at 3.5 A or greater. In... 

An example of this problem is provided by our work on the interaction of urea and thiourea with crown ethers[23]. Five crystal structures have been carried out on these systems (18-crown-6)(thiourea)2, [24] (18-crown-6)(urea)5, [25], (18-crown-6)(N-methylthiourea) [26], (18-crown-6)(chlorophenylurea)2, [27] and (18-crown-6)(thiourea)4 [28]. In all these structures there are intermolecular hydrogen bonds between the amine hydrogen atoms and the oxygen atoms in the 18-crown-6. The pattern of hydrogen bonds is different in the five structures. 

Pavletich, N.P., Pabo, C.O. Crystal structure of a five-finger GLI-DNA complex new perspectives on zinc fingers. Science 261 1701-1707, 1993. 

In contras t with dially lamines and their sulfonyl derivatives, IV-acy Idially lamines react with tellurium tetrahalides to give zwitterionic oxazolines 29 containing five-coordinated tellurium (85T1607). Molecular and crystal structures of one of this type of compound (29, R = Me, X = Cl) were studied by X-rays (85T1607). 

Crystal Structures of Five-Ring OPVs 16.3.1.2.1 Ooct-OPV5... 

Conti et al. (1996) solved the crystal structure of the P. pyralis luciferase at 2.0 A resolution. The protein is folded into two compact domains, a large N-terminal portion and a small C-terminal portion. The former portion consists of a /1-barrel and two /1-sheets. The sheets are flanked by a-helices to form an aflafia five-layered structure. The C-terminal portion of the molecule forms a distinct domain, which is separated from the N-terminal domain by a wide cleft. It is suggested that the two domains will close up in the course of the luminescence reaction. 

The x-ray crystal structures of the hexaethyl- and hexabutenylbenzene complexes show noteworthy conformational effects [78] (Fig. 6). The hexaethylbenzene complex has four distal chains [76] contrary to all the previous conformations of C6Et6 and (M)C6Et6 of C3 symmetry. This conformation also depends on the counter-anion as the three conformations with four, five, and six distal ET groups have close energies and can be observed by low-temperature 1H NMR. The hexabutenyl benzene complex has five distal chains [77]. 

Revised Values of Double-Bond Covalent Radii.—This investigation has led to the value 1.34 A. for the carbon-carbon double-bond distance, 0.04 A. less than the value provided by the table of covalent radii.111 4 Five years ago, when this table was extended to multiple bonds, there were few reliable experimental data on which the selected values for double-bond and triple-bond radii could be based. The single-bond radii were obtained -from the study of a large number of interatomic distances found experimentally by crystal-structure and spectroscopic methods. The spectroscopic value of the triple-bond radius of nitrogen (in N2) was found to bear the ratio 0.79 to the single-bond radius, and this ratio was as-... 

The properties and characteristics of the five HNLs used as catalysts in stereoselective syntheses are listed in Table 2. The crystal structures of these HNLs have been determined during the last decade. From the crystal structures and kinetic measurements, the mechanistic pathways of cyanogenesis could be established. 

Synthesis and crystal structure of the novel five-membered cycloaurated complex of l-efhyl-2-phenylimidazole. 

Figure 18.4 Structures of heme/Cu oxidases at different levels of detail, (a) Position of the redox-active cofactors relative to the membrane of CcO (left, only two obligatory subunits are shown) and quinol oxidase (right), (b) Electron transfer paths in mammalian CcO. Note that the imidazoles that ligate six-coordinate heme a and the five-coordinate heme are linked by a single amino acid, which can serve as a wire for electron transfer from ferroheme a to ferriheme as. (c) The O2 reduction site of mammalian CcO the numbering of the residues corresponds to that in the crystal structure of bovine heart CcO. The subscript 3 in heme as and heme 03 signifies the heme that binds O2. The structures were generated using coordinates deposited in the Protein Data Bank, lari [Ostermeier et al., 1997] Ifft [Abramson et al., 2000] (a) and locc [Tsukihara et al., 1996] (b, c).

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