An Adenosine Triphosphate-dependent Deoxyribonuclease from Hemophilus influenzae Rd
1972; Elsevier BV; Volume: 247; Issue: 9 Linguagem: Inglês
10.1016/s0021-9258(19)45289-7
ISSN1083-351X
AutoresHamilton O. Smith, Eileen Friedman,
Tópico(s)ATP Synthase and ATPases Research
ResumoThe ATP-dependent DNase of Hemophilus injfuenzae Rd acts as a DNA-dependent ATPase which splits ATP into ADP and inorganic phosphate in the presence of magnesium ions and DNA.The apparent K, for ATP in the ATPase reaction is 0.18 mM.Approximately 40 ATP molecules are utilized for each DNA phosphodiester bond cleaved.All of the common ribose and deoxyribose nucleoside 5'-triphosphates can replace ATP in the DNase reaction with varying degrees of effectiveness ranging from 40 to 90 %.The DNase from Hemophilus influenzae described in the preceding article (1) has the unusual property that it requires ATP for its nuclease action.In this paper we examine the role of ATP in the reaction.It is shown that the enzyme is an active DNA-dependent ATPase which converts ATP into ADP.The over-all properties of the ATPase activity are similar to those described by Anai et al. ( 2) for the nucleoside triphosphate requiring DNase from il!l~crococcus lysodeikticus.EXPERIMENTAL PROCEDURE Materials Chemicals, Enzymes, and Radioactive Compounds-Bacterial alkaline phosphatase was obtained from Worthington and repurified as described by Weiss et al. (3).[8JH]ATP, 20.7 Ci per InM, and [8JH]ADP, 20.3 Ci per mM, were obtained from Schwarz-Mann.ATP was obtained from Calbiochem.dATP, ADP, AMP, dGTP, dTTP, dCTP, GTP, UTP, and CTP were obtained from Sigma.a, fl-Methylene ATP and /3, y-methylene ATP were obtained from Miles Laboratories, Inc., Research Products Division.[
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