Kinetics of TmHU binding to DNA as observed by optical tweezers.
The kinetics of binding for the histone-like protein TmHU (from Thermotoga maritima) to DNA is analyzed on a single molecule level by use of optical tweezers. For the reaction rate a pronounced concentration-dependence is found with an "all or nothing"-limit which suggests the cooperative nature of the binding-reaction. By analyzing the statistics of mechanically induced dissociation-events of TmHU from DNA multiple reaction sites are observed to become more likely with increasing TmHU concentration. This is interpreted as a hint for a secondary organizational level of the TmHU/DNA complex. The reaction rate of TmHU binding to DNA is remarkably higher than that of the HU protein from Escherichia coli which will be discussed.
Salomo
Mathias
M
Faculty of Experimental Physics 1, University of Leipzig, Linnèstrasse 5, D-04103 Leipzig, Germany. msalomo@rz.uni-leipzig.de
Keyser
Ulrich F
UF
Kegler
Kati
K
Gutsche
Christof
C
Struhalla
Marc
M
Immisch
Claudia
C
Hahn
Ulrich
U
Kremer
Friedrich
F
D001426:Bacterial Proteins / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000378:metabolism; D052898:Optical Tweezers; D011485:Protein Binding; D020124:Thermotoga maritima / Q000737:chemistry*
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C116822:hns protein, E coli; D004247:DNA