| Autor: |
Biswas I; Genetics and Biochemistry Branch, NIDDK, National Institutes of Health, Bethesda, Maryland 20892, USA., Ban C, Fleming KG, Qin J, Lary JW, Yphantis DA, Yang W, Hsieh P |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of biological chemistry [J Biol Chem] 1999 Aug 13; Vol. 274 (33), pp. 23673-8. |
| DOI: |
10.1074/jbc.274.33.23673 |
| Abstrakt: |
The MutS DNA mismatch protein recognizes heteroduplex DNAs containing mispaired or unpaired bases. We have examined the oligomerization of a MutS protein from Thermus aquaticus that binds to heteroduplex DNAs at elevated temperatures. Analytical gel filtration, cross-linking of MutS protein with disuccinimidyl suberate, light scattering, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry establish that the Taq protein is largely a dimer in free solution. Analytical equilibrium sedimentation showed that the oligomerization of Taq MutS involves a dimer-tetramer equilibrium in which dimer predominates at concentrations below 10 microM. The DeltaG(0)(2-4) for the dimer to tetramer transition is approximately -6.9 +/- 0.1 kcal/mol of tetramer. Analytical gel filtration of native complexes and gel mobility shift assays of an maltose-binding protein-MutS fusion protein bound to a short, 37-base pair heteroduplex DNA reveal that the protein binds to DNA as a dimer with no change in oligomerization upon DNA binding. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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