Cluster molecular basis

Becker, J.E., Moore, R.E. and Moore, B.S. (2004) Cloning, sequencing, and biochemical characterization of the nostocyclopeptide biosynthetic gene cluster molecular basis for imine macrocyclization. Gene, 325, 35 42. 

Since their discovery, Rieske proteins have been the object of numerous studies aimed at gaining insight into the molecular basis of their unique properties. These studies not only have shed light on Rieske and Rieske-type clusters, but also have contributed to the understanding of iron sulfur proteins in general. 

Molecules and Clusters. The local nature of the effective Hamiltonian in the LDF equations makes it possible to solve the LDF equations for molecular systems by a numerical LCAO approach (16,17). In this approach (17), the atomic basis functions are constructed numerically for free atoms and ions and tabulated on a numerical grid. By construction, the molecular basis becomes exact as the system dissociates into its atoms. The effective potential is given on the same numerical grid as the basis functions. The matrix elements of the effective LDF Hamiltonian in the atomic basis are given by... 

The chemist also wishes to relate samples in a similar manner. Can protein sequences from different animals be related and does this tell us about the molecular basis of evolution Can the chemical fingerprint of wines be related and does this tell us about the origins and taste of a particular wine Unsupervised pattern recognition employs a number of methods, primarily cluster analysis, to group different samples (or objects) using chemical measurements. 

Sphalerite (p-ZnS) has a cubic crystal structure in which both Zn and S occur in regular tetrahedral coordination. Pure sphalerite is a diamagnetic semiconductor with a large band gap (—3.6 eV Shuey, 1975). On the basis of the observed structure and properties, the simple MO energy-level diagram shown in Fig. 6.1 can be proposed to describe the bonding in a ZnS4 cluster molecular unit. Overlaps between outermost s and p... 

Our preliminary experiments on whole cells show that the molecular basis of the FNR inactivation in aerobic medimn, namely the [4Fe-4S] + cluster degradation via a [2Fe-2S] intermediate, previously deduced from studies of purified FNR, is valid also in vivo. It is not yet clear whether the 4Fe 2Fe cluster conversion observed in vitro as well as in vivo puts the protein in a ready state from which the 4Fe cluster can be rebuilt once the bacterial environment becomes anaerobic again. Conceivably, the [2Fe-2S] cluster may be just an intermediate in the pathway of complete aerobic degradation of the 4Fe-4S cluster. These are questions which need to be addressed by future studies. 

When alamethicin is examined by the techniques used for observing single channels, complex step-like current fluctuations are seen in which not all the current levels are equally probable and not all the current steps are of equal size [29]. Hie molecular basis of the events which underlie this behaviour is not fully resolved. The results have been interpreted in ways which suggest that interaction occurs between the individual channels, perhaps by some form of clustering. Presumably then clusters of one size are more probable than others, and also the formation of clusters may alter the conductance of individual channels. Both of these properties would produce the sort of behaviour seen with alamethicin channels. 

Journal of Physical Chemistry A. - The Journal of Physical Chemistry is devoted to reporting new and original experimental and theoretieal basie researeh of interest to physieal ehemists and chemical physicists. The Journal of Physical Chemistry A publishes studies on molecules (dynamics, spectroscopy, gaseous clusters, molecular beams, kinetics, atmospheric and environmental physical chemistry, molecular structure, bonding, quantum chemistry, and general theory). 

Martins JBL, Andres J, Longo E, Taft CA (1995) A theoretical-study of (1010) and (0001) ZnO surfaces—molecular cluster model, basis-set and effective core potential dependence. Theochem-J Mol Struc 330 301-306... 

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