Effect of divalent cations on the ATPase activity of Escherichia coli SecA.
It was found that Ca(2+) stimulates the intrinsic SecA ATPase activity in the absence as well as in the presence of liposome. On the other hand, Mg(2+), the general cofactor for ATPase, did not affect the intrinsic SecA ATPase but reduced the portion of ATPase activity enhanced by Ca(2+). The enhancement of SecA ATPase activity correlated well with the increase in 8-anilino-1-naphthalene-sulfonic acid binding of SecA, suggesting that increased exposure of hydrophobic residues stimulates the enzyme activity.
Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 373-1 Kusong-Dong, Yusong-Gu, 305-701, Taejon, South Korea.
J
J
Kim
T
T
Ahn
J
J
Ko
C
C
Park
H
H
Kim
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000817:Anilino Naphthalenesulfonates / Q000494:pharmacology; D001426:Bacterial Proteins; D002118:Calcium / Q000378:metabolism*; D002122:Calcium Chloride / Q000494:pharmacology; D002352:Carrier Proteins / Q000378:metabolism*; D002412:Cations; D002462:Cell Membrane / Q000378:metabolism; D002614:Chelating Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004926:Escherichia coli / Q000201:enzymology* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes / Q000494:pharmacology; D007700:Kinetics; D008024:Ligands; D008081:Liposomes / Q000378:metabolism; D008274:Magnesium / Q000378:metabolism; D026901:Membrane Transport Proteins; D011485:Protein Binding; D000069816:SEC Translocation Channels; D000081416:SecA Proteins; D013696:Temperature
D000817:Anilino Naphthalenesulfonates; D001426:Bacterial Proteins; D002352:Carrier Proteins; D002412:Cations; D002614:Chelating Agents; D029968:Escherichia coli Proteins; D005456:Fluorescent Dyes; D008024:Ligands; D008081:Liposomes; D026901:Membrane Transport Proteins; D000069816:SEC Translocation Channels; C027132:1-anilino-8-naphthalenesulfonate; D000251:Adenosine Triphosphatases; D000081416:SecA Proteins; D008274:Magnesium; D002122:Calcium Chloride; D002118:Calcium