Nucleotides binding sites

Latrunculins A and B are macrolides from the sponge Latrunculia magnified. Latrunculin A (>50 11M) binds close to the nucleotide binding site of G-actin and blocks the assembly with F-actin without promoting disassembly. 

Metal complexes of nucleic acid derivatives and nucleotides binding sites and structures. L. G. Marzilli, Adv. Inorg. Biochem., 1981, 3, 48-85 (138). 

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. 

Synthetic nonhydrolyzable analogs of nucleoside triphosphates (Figure 33-13) allow investigators to distinguish the effects of nucleotides due to phosphoryl transfer from effects mediated by occupancy of allosteric nucleotide-binding sites on regulated enzymes. 

Comparison with the nucleotide binding sites in adenylate kinase... 

The estimated distances between lanthanides bound at various cation binding sites on the Ca -ATPase, and FITC, TNP-ATP, Cr-ATP or eosin bound at the nucleotide binding site range between 10 and 47 A [389,390,400,401,407-409,413] (Table II). 

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. 

The GDP is replaced at the nucleotide-binding site by guanosine triphosphate (GTP), which is present in a three to fourfold excess (50-300 u. I) in the cytosol. 

Urbatsch, I. L., Sankaran, B., Bhagat, S., Senior, A. E., Both P-glycoprotein nucleotide-binding sites are catalytically active, J. Biol. Chem. 1995, 270, 26956-26961. 

When the receptor interacts with its associated G protein, the conformation of the guanine-nucleotide-binding site is altered. The subunits then dissociate, and a phosphatidylinositol-specific phospholipase C (PI-PLC) is activated [5]. The subsequent hydrolysis of phosphatidylinositol bisphosphate then produces inositol triphosphate (IP3) and diacylglycerol (DAG), which are known to be secondary messengers. For example, the water soluble IP3 is released into the cell where its ultimate targets are the calcium storage organelles from which Ca2+ is released [3]. The presence of DAG in cells is known to activate the cellular enzyme protein kinase C (PKC) [6, 7], which phosphorylates a number of cellular... 

S., Lerner-Marmarosh, N., Rousseau, M.E., Gros, P. and Senior, A.E. (2001) Cysteines 431 and 1074 are responsible for inhibitory disulfide cross-linking between the two nucleotide-binding sites in human P-glycoprotein. Journal of Biological Chemistry, 276, 26980-26987. 

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