Mutational studies

Early mutational studies of the Rieske protein from 6ci complexes have been performed with the intention of identifying the ligands of the Rieske cluster. These studies have shown that the four conserved cysteine residues as well as the two conserved histidine residues are essential for the insertion of the [2Fe-2S] cluster (44, 45). Small amounts of a Rieske cluster with altered properties were obtained in Rhodobacter capsulatus when the second cysteine in the cluster binding loop II (Cys 155, corresponding to Cys 160 in the bovine ISF) was replaced by serine (45). The fact that all four cysteine residues are essential in Rieske clusters from be complexes, but that only two cysteines are conserved in Rieske-type clusters, led to the suggestion that the Rieske protein may contain a disulfide bridge the disulfide bridge was finally shown to exist in the X-ray structure (9). 

It has been argued that using several A parameters A0, A(,. .., L one can perform several mutation studies simultaneously in so-called competitive binding experiments [57]. This approach allows the calculation of AAy for any two ligands and rapid ranking of compounds according to their binding affinity. In this case, the potential U is defined as... 

KUSHIRO, T., SHIBUYA, M., MASUDA, K., EBIZUKA, Y., Mutational studies of triterpene synthases Engineering lupeol synthase into (3-amyrin synthase, J. Am. Chem. fee., 2000,122, 6816-6824. 

V79 System. The Chinese hamster V79 line was established in 1958 (Ford and Yerganian, 1958). Publication of the use of the line for mutation studies (by measuring resistance to purine analogues due to mutation of the Hgprt locus) occurred 10 years later (Chu and Mailing, 1968). The V79 line was derived from a male Chinese hamster hence, V79 cells possess only a single X chromosome. 

Ho, B.Y., Karschin, A., Branchek, T., Davidson, N. and Lester, H.A. (1992) The role of conserved aspartate and serine residues in ligand binding and in function of the 5-HT1A receptor a site-directed mutation study. FEBS Letters, 312, 259-262. 

In agreement with the findings from microbial gene mutation studies with mirex, there is no evidence that chlordecone is a mutagen for S. typhimurium or E. coli (Mortelmans et al. 1986 Probst et al. 1981 Schoeny et al. 1979). Similarly, chlordecone alcohol, the major metabolite of chlordecone in humans, is not mutagenic in S. typhimurium (Mortelmans et al. 1986). 

K V. Mechanistic and mutational studies of Escherichia coli molybdopterin synthase clarify the final step of molybdopterin biosynthesis,... 

An E2 needs to associate with several different proteins in the course of the ubiquitin conjugation cascade, with the first being the El. Mutational studies con-... 

Moeodee, L., and Hubee, R. Mutational studies on HslU and its docking mode with HslV. Proc. Natl. Acad. Sci. USA 2000, 97, 14103-14108. 

Molecular targets have been elucidated for Dm-AMPl and Rs-AFP2. Dm-AMPl was found to bind plasma membranes from Neurospora crassa and Saccharomyces cerevisiae in a saturable manner and it competed with closely related defensins for binding. Mutational studies with S. cerevisiae identified lipid raffs containing sphingolipids as a molecular target " while glycosylphosphatidylinositol (GPI)-anchored proteins could be... 

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