Proteolytic studies on the transduction mechanism of sarcoplasmic reticulum Ca2+-ATPase: common features with other P-type ATPases
| Autor: | Jesper V, Møller, Guillaume, Lenoir, Marc, Le Maire, Birte Staehr, Juul, Philippe, Champeil |
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| Rok vydání: | 2003 |
| Předmět: |
Binding Sites
Sequence Homology Amino Acid Molecular Sequence Data Biological Transport Active Calcium-Transporting ATPases Models Theoretical Recombinant Proteins Sarcoplasmic Reticulum Calcium-Transporting ATPases Substrate Specificity Kinetics Mutagenesis Site-Directed Animals Calcium Amino Acid Sequence Endopeptidase K Sequence Alignment |
| Zdroj: | Annals of the New York Academy of Sciences. 986 |
| ISSN: | 0077-8923 |
| Popis: | After proteinase K-induced excision of five amino acid residues in the semiconserved polypeptide chain linking the end of the A domain with the S3/M3 transmembrane segment we find that Ca(2+) transport is blocked while partial reactions like Ca(2+) binding, ATP phosphorylation, and Ca(2+)-occlusion are left intact. However, formation of the so-called E2P state (either from the phosphorylated species formed in the presence of ATP and Ca(2+) or from the Ca(2+)-depleted unphosphorylated species) is blocked. We conclude that the proteinase K-treated ATPase, while maintaining many of the partial reactions, is incapable of energy transduction because of the absence of an E2P state with Ca(2+) binding sites exposed to the intravesicular space. Sequence comparisons and mutagenesis data point to an important role in energy transduction of P-type ATPases of a conserved motif located at the end of the A domain. |
| Databáze: | OpenAIRE |
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