Matches in SemOpenAlex for { <https://semopenalex.org/work/W2899463930> ?p ?o ?g. }
Showing items 1 to 73 of
73
with 100 items per page.
- W2899463930 abstract "Site-specific recombination is a process employed by organisms in order to perform spatially and temporally defined rearrangement of DNA molecules, such as phage integration and excision, resolution of circular multimers, inversions for expression of alternate genes, and assembly of genes during development. Tn3R is the prototype of a family of closely related mobile genetic elements referred to as the class II or Tn3 family of transposons. Tn3 contains the genes encoding a transposase, β-lactamase, and a site-specific recombinase, Tn3 resolvase (Tn3R), that is responsible for the resolution of the cointe-grate, an intermediate in the transposition reaction. Tn3R is able to resolve in vitro supercoiled plasmids containing two 114 bp res sites in direct orientation into two smaller circular plasmids, each of them with a single res site. In this thesis, the solution properties of Tn3R were studied by sedimentation equilibrium (SE) and velocity (SV) analytical ultracentrifugation and small angle neutron scattering (SANS). Tn3R was found to be in a monomer-dimer self-association equilibrium, with a dissociation constant of kD1-2= 50 μM. SV and SANS demonstrated that the low-resolution conformation of dimeric Tn3R in solution is similar to that of γδ resolvase in the co-crystal structure by Yang and Steitz (1995), but with the DNA-binding domains in a rather extended conformation. In addition, equilibrium binding of Tn3R to the individual binding sites in res (sites I, II and III) was investigated by employing fluorescence anisotropy (FA) measurements. This revealed that site IIL (site II left end) and site III have the highest affinity for Tn3R, followed by site I, and finally by site HR (site II right end). The specificity of binding of Tn3R for non-specific DNA was assayed by competition experiments, where it was shown that the affinity of binding of Tn3R to site I is 1000 times higher than to non-specific sites. A new approach, involving a combination of rigid-body and ab initio modelling was developed for the study of the solution structure of macromolecules. At first, this approach was tested by applying it to the reconstruction of the low-resolution solution conformation of a DNA Holiday junction, based on small angle x-ray scattering and sedimentation velocity data. The scattering data were analysed in two independent ways: firstly, by rigid body modelling using previously suggested models for the Holliday junction (HJ), and secondly, by ab initio reconstruction methods. Sedimentation coefficients calculated for the models generated by both methods agreed with those determined experimentally and were compatible with the results of previous studies using different techniques, but provided a more direct and accurate determination of the solution conformation of the HJ. These results confirmed that addition of Mg2+ alters the conformation of the HJ from an extended to a stacked arrangement. The solution conformation of a stable protein-DNA complex formed by a mutant of Tn3R and DNA was studied by a similar approach. Hyperactive mutants of resolvase form a complex (X-synapse) containing two site I DNA fragments and a resolvase tetramer. The low-resolution solution structure of the purified, catalytically competent X-synapse was solved from small angle neutron and x-ray scattering data, by fitting the models constructed by rigid-body transformations of a published crystallographic structure of a resolvase dimer bound to site I to the data. This analysis revealed that the two site I fragments are on the outside of a resolvase tetramer core, and provided some information on the quaternary structure of the tetramer. Finally, the rigid-body modelling method was redesigned into a general systematic approach to retrieve the conformation of a macro molecule that simultaneously agrees with a range of experimental solution properties. In this method, generalised rigid-body modelling was combined with a Monte Carlo/simulated annealing optimisation method to search over a large range of possible conformations for the structure that best fits solution experimental properties derived from small angle scattering, fluorescence resonance energy transfer, and analytical ultracentrifugation datasets. This improved methodology was evaluated by applying it to two bulged DNA fragments with very different solution conformations." @default.
- W2899463930 created "2018-11-09" @default.
- W2899463930 creator A5009574425 @default.
- W2899463930 date "2004-01-01" @default.
- W2899463930 modified "2023-09-27" @default.
- W2899463930 title "Biophysical studies on Tn3 resolvase" @default.
- W2899463930 hasPublicationYear "2004" @default.
- W2899463930 type Work @default.
- W2899463930 sameAs 2899463930 @default.
- W2899463930 citedByCount "0" @default.
- W2899463930 crossrefType "dissertation" @default.
- W2899463930 hasAuthorship W2899463930A5009574425 @default.
- W2899463930 hasConcept C102414288 @default.
- W2899463930 hasConcept C104317684 @default.
- W2899463930 hasConcept C105793898 @default.
- W2899463930 hasConcept C107824862 @default.
- W2899463930 hasConcept C119898374 @default.
- W2899463930 hasConcept C141231307 @default.
- W2899463930 hasConcept C14430832 @default.
- W2899463930 hasConcept C156695909 @default.
- W2899463930 hasConcept C158456008 @default.
- W2899463930 hasConcept C185592680 @default.
- W2899463930 hasConcept C4918238 @default.
- W2899463930 hasConcept C552990157 @default.
- W2899463930 hasConcept C55493867 @default.
- W2899463930 hasConcept C71240020 @default.
- W2899463930 hasConcept C73573662 @default.
- W2899463930 hasConcept C8010536 @default.
- W2899463930 hasConcept C86803240 @default.
- W2899463930 hasConceptScore W2899463930C102414288 @default.
- W2899463930 hasConceptScore W2899463930C104317684 @default.
- W2899463930 hasConceptScore W2899463930C105793898 @default.
- W2899463930 hasConceptScore W2899463930C107824862 @default.
- W2899463930 hasConceptScore W2899463930C119898374 @default.
- W2899463930 hasConceptScore W2899463930C141231307 @default.
- W2899463930 hasConceptScore W2899463930C14430832 @default.
- W2899463930 hasConceptScore W2899463930C156695909 @default.
- W2899463930 hasConceptScore W2899463930C158456008 @default.
- W2899463930 hasConceptScore W2899463930C185592680 @default.
- W2899463930 hasConceptScore W2899463930C4918238 @default.
- W2899463930 hasConceptScore W2899463930C552990157 @default.
- W2899463930 hasConceptScore W2899463930C55493867 @default.
- W2899463930 hasConceptScore W2899463930C71240020 @default.
- W2899463930 hasConceptScore W2899463930C73573662 @default.
- W2899463930 hasConceptScore W2899463930C8010536 @default.
- W2899463930 hasConceptScore W2899463930C86803240 @default.
- W2899463930 hasLocation W28994639301 @default.
- W2899463930 hasOpenAccess W2899463930 @default.
- W2899463930 hasPrimaryLocation W28994639301 @default.
- W2899463930 hasRelatedWork W1512397531 @default.
- W2899463930 hasRelatedWork W1517989579 @default.
- W2899463930 hasRelatedWork W1971432236 @default.
- W2899463930 hasRelatedWork W1977799538 @default.
- W2899463930 hasRelatedWork W1978686942 @default.
- W2899463930 hasRelatedWork W1979150783 @default.
- W2899463930 hasRelatedWork W1998276835 @default.
- W2899463930 hasRelatedWork W1998492178 @default.
- W2899463930 hasRelatedWork W2004821320 @default.
- W2899463930 hasRelatedWork W2008380486 @default.
- W2899463930 hasRelatedWork W2032580068 @default.
- W2899463930 hasRelatedWork W2039243189 @default.
- W2899463930 hasRelatedWork W2066191278 @default.
- W2899463930 hasRelatedWork W2075146689 @default.
- W2899463930 hasRelatedWork W2084165318 @default.
- W2899463930 hasRelatedWork W2413639218 @default.
- W2899463930 hasRelatedWork W262305830 @default.
- W2899463930 hasRelatedWork W3193729306 @default.
- W2899463930 hasRelatedWork W3199682393 @default.
- W2899463930 hasRelatedWork W2071697090 @default.
- W2899463930 isParatext "false" @default.
- W2899463930 isRetracted "false" @default.
- W2899463930 magId "2899463930" @default.
- W2899463930 workType "dissertation" @default.