Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.3.1 (Mg2+-ATPase)
 1,484 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Actin from Tetrahymena pyriformis has been purified by monitoring the presence of the actin gene product with an antiserum against a synthetic N-terminal peptide deduced from the nucleotide sequence of the Tetrahymena actin gene that we cloned previously. This highly purified Tetrahymena actin shares many essential properties with ubiquitous actin, including ion-dependent polymerization to microfilaments, binding with muscle heavy meromyosin to form arrowheads, and activation of the Mg2+-ATPase of muscle myosin subfragment 1. On the other hand, some properties of this purified Tetrahymena actin clearly differ from those of muscle actin: (i) Tetrahymena actin has 8 times less ability to activate the Mg2+-ATPase of muscle myosin subfragment 1 than muscle actin; (ii) Tetrahymena actin did not bind to phalloidin at all; (iii) Tetrahymena actin did not inhibit DNase I activity at all. In general, Tetrahymena actin has very unusual properties when compared to other actins described so far. This actin is expected to provide important clues for elucidating problems concerning the relationships between the structural and functional domains in an actin molecule.
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PMID:Purification of Tetrahymena actin reveals some unusual properties. 252 89

Actin from amebae of Naegleria gruberi has been purified to homogeneity. The purified actin shares many attributes with numerous other actins that have been characterized, including molecular weight, strong binding to DEAE-cellulose, binding to DNase I, reversible polymerization to F-actin, binding of rabbit myosin subfragment 1 to give distinctive arrowheads , formation of Mg paracrystals, and activation of myosin Mg2+-ATPase. In two respects the attributes of Naegleria actin are unusual. Isoelectric focusing resolves three distinct isoforms of the actin, which raises questions about the function of multiple isoforms in a unicellular eukaryote. The amino acid composition closely resembles other actins except that Naegleria actin lacks N tau-methylhistidine. This result indicates that N tau-methylhistidine is not a prerequisite for actin-actin or actin-myosin interactions.
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PMID:Actin of Naegleria gruberi. Absence of N tau-methylhistidine. 623 84