recA protein from Escherichia coli. A very rapid and simple purification procedure: binding of adenosine 5'-triphosphate and adenosine 5'-diphosphate by the homogeneous protein
- 1 August 1982
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 21 (18) , 4332-4337
- https://doi.org/10.1021/bi00261a023
Abstract
The recA protein from E. coli may be rapidly purified to homogeneity by a simple procedure involving only selective precipitation and 1 gel filtration step. The binding of ATP to the homogeneous protein was measured by nonequilibrium dialysis. At pH 8.1 and 25.degree. C, the stoichiometry of the recA.cntdot.ATP complex is 1:1 and the dissociation constant 24 .mu.M. The binding of ADP to the enzyme and its complexes with single-stranded (ss) DNA and double-stranded (ds) DNA was measured by equilibrium dialysis. In the absence of DNA, the binding is similar to that observed for ATP. The addition of ssDNA weakens the binding 3-fold. The addition of dsDNA causes a significant drop in the stoichiometry, suggesting an asymmetric distribution of active sites in the complex.This publication has 1 reference indexed in Scilit:
- [10] Assay of inorganic phosphate, total phosphate and phosphatasesPublished by Elsevier ,1966