ATP Binding Residues of Sarcoplasmic Reticulum Ca2+-ATPase
| Autor: | Johannes D. Clausen, David H. MacLennan, David G. Woolley, Jens Peter Andersen, David B. McIntosh, Bente Vilsen |
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| Rok vydání: | 2003 |
| Předmět: |
Models
Molecular ATPase Static Electricity Calcium-Transporting ATPases Protein Structure Secondary General Biochemistry Genetics and Molecular Biology Sarcoplasmic Reticulum Calcium-Transporting ATPases Residue (chemistry) Adenosine Triphosphate History and Philosophy of Science Animals Nucleotide Amino Acid Sequence Conserved Sequence chemistry.chemical_classification Binding Sites biology General Neuroscience Endoplasmic reticulum Ligand binding assay Mutagenesis Peptide Fragments Recombinant Proteins Amino Acid Substitution Biochemistry chemistry biology.protein |
| Zdroj: | Annals of the New York Academy of Sciences. 986:101-105 |
| ISSN: | 1749-6632 0077-8923 |
| Popis: | ATP-binding residues in the N and P domains of sarcoplasmic reticulum Ca-ATPase have been investigated using mutagenesis in combination with a binding assay based on the photolabeling of Lys(492) with [g-(32)P] 2',3'-O-(2,4,6 trinitrophenyl)-8-azido-ATP and competition with nucleotide. In the N domain, mutations to several residues in conserved motifs, (438)GEATE, (487)FSRDRK, (515)KGAPE, and (560)RCLALA produce nucleotide-binding defects. Key residues include Thr(441), Glu(442), Phe(487), Arg(489), Lys(492), Lys(515), Arg(560), and Leu(562). In the absence of Mg(2+), Arg(489), Lys(492), and Arg(560) are most important, whereas in its presence Thr(441) and Glu(442) also play a crucial role. In the P domain, Asp(351) is striking for its strong electrostatic repulsion of the gamma-phosphate, especially in the presence of Mg(2+). Lys(352) is a key residue, and Asp(627) and Lys(684) must come close to the nucleotide. Thr(353), Asn(359), Asp(601), and Asp(703) interact only in the presence of Mg(2+). Asn(706) and Asp(707) are unimportant for nucleotide binding. The results identify several ATP binding residues in the N and P domains and suggest that Mg(2+) changes the nucleotide/protein interaction in both. Models of bound ATP and MgATP are presented. |
| Databáze: | OpenAIRE |
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