06/2004 - Crystal structure of the quorum-sensing protein TraM and its interaction with the transcriptional regulator TraR
Transfer of the tumor-inducing plasmid in Agrobacterium tumefaciens is controlled by a quorum-sensing system whose main components are the transcriptional regulator TraR and its autoinducer. This system allows bacteria to synchronize infection of the host plant when a “quorum” of cells has been reached. TraM is an A. tumefaciens protein involved in the regulation of […]
02/2004 - Mechanism of activation of human heparanase investigated by protein engineering
The aim of this study was to investigate the mechanism of activation of human heparanase, a key player in heparan sulfate degradation, thought to be involved in normal and pathologic cell migration processes. Active heparanase arises as a product of a series of proteolytic processing events. Upon removal of the signal peptide, the resulting, poorly […]
01/2004 - Crystallization and preliminary X-ray diffraction studies of the quorum-sensing regulator TraM from Agrobacterium tumefaciens
TraM is a 11.4 kDa protein involved in the control of the conjugal transfer of Agrobacterium tumefaciens Ti plasmids by quorum-sensing. TraM was overexpressed and purified from Escherichia coli. This protein binds to the transcriptional regulator TraR, abolishing its function. Size-exclusion chromatography and dynamic light scattering show that the recombinant protein has an apparent molecular […]
11/2003 - The effects of heavy metal contamination on the soil arthropod community of a shooting range
Soils in clay pigeon shooting ranges can be seriously contaminated by heavy metals. The pellets contained in ammunition are composed of Pb, Sb, Ni, Zn, Mn and Cu. The total concentrations of these metals in soils, and the effects of their increasing levels on the arthropod community were investigated at seven sampling sites in a […]
10/2002 - Determination of the stoichiometry of noncovalent complexes using reverse-phase high-performance liquid chromatography coupled with electrospray ion trap mass spectrometry
An electrospray mass spectrometry-based methodology has been developed to have a fast and sensitive method for protein-cofactor stoichiometry determination. As model systems, we used two proteins which require the presence of cofactors for activity: TraR, a member of the LuxR family of quorum-sensing transcriptional regulators, which requires an acyl-homoserine lactone molecule called Agrobacterium autoinducer (AAI) […]
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