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.
Faculty of Experimental Physics 1, University of Leipzig, Linnèstrasse 5, D-04103 Leipzig, Germany. msalomo@rz.uni-leipzig.de
Mathias
M
Salomo
Ulrich F
UF
Keyser
Kati
K
Kegler
Christof
C
Gutsche
Marc
M
Struhalla
Claudia
C
Immisch
Ulrich
U
Hahn
Friedrich
F
Kremer
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