Nucleotides conformational changes

Studies (113) on Fe protein with an Asp39Asn mutation in the nucleotide binding site indicate that the conformational change observed in the crystal structure of the complex is dependent on electron treuis-fer from the Fe protein to the MoFe protein. 

The process of RNA synthesis in bacteria—depicted in Figure 37-3—involves first the binding of the RNA holopolymerase molecule to the template at the promoter site to form a PIC. Binding is followed by a conformational change of the RNAP, and the first nucleotide (almost always a purine) then associates with the initiation site on the 3 subunit of the enzyme. In the presence of the appropriate nucleotide, the RNAP catalyzes the formation of a phosphodiester bond, and the nascent chain is now attached to the polymerization site on the P subunit of RNAP. (The analogy to the A and P sites on the ribosome should be noted see Figure... 

How can hydrolysis of ATP produce macroscopic movement Muscle contraction essentially consists of the cychc attachment and detachment of the S-1 head of myosin to the F-actin filaments. This process can also be referred to as the making and breaking of cross-bridges. The attachment of actin to myosin is followed by conformational changes which are of particular importance in the S-1 head and are dependent upon which nucleotide is present (ADP or ATP). These changes result... 

Binding of the receptor induces a rapid conformational change (switch) in the G-protein trimer. This is transmitted to the nucleotide binding site, about 3 nm away, and results in a dissociation of bound GDP. 

Wang, J., Song, J. J., Seong, I. S., Franklin, M. C., Kamtekar, S., Eom, S. H., and Chung, C. H. Nucleotide-dependent conformational changes in a protease-associated ATPase HslU. Structure fCambJ 2001b, 9, 1107-1116. 

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