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LysR-type Transcriptional Regulator (lysr-type + transcriptional_regulator)

Distribution by Scientific Domains
Chemistry100%

Selected Abstracts

The oligomerization of CynR in Escherichia coli

PROTEIN SCIENCE, Issue 11 2009
Gwendowlyn S. Knapp
Abstract Deletion analysis and alanine-scanning based on a homology-based interaction model were used to identify determinants of oligomerization in the transcriptional regulator CynR, a member of the LysR-type transcriptional regulator (LTTR) family. Deletion analysis confirmed that the putative regulatory domain of CynR was essential for driving the oligomerization of , repressor-CynR fusion proteins. The interaction surface of a different LTTR and OxyR was mapped onto a multiple sequence alignment of the LTTR family. This mapping identified putative contacts in the CynR regulatory domain dimer interface, which were targeted for alanine-scanning mutagenesis. Oligomerization was assayed by the ability of mutant , repressor-CynR fusions to assemble in E. coli revealing interesting similarities and differences between OxyR and CynR. [source]

Oligomerization of BenM, a LysR-type transcriptional regulator: structural basis for the aggregation of proteins in this family

ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 5 2007
Sandra Haddad
LysR-type transcriptional regulators comprise the largest family of homologous regulatory DNA-binding proteins in bacteria. A problematic challenge in the crystallization of LysR-type regulators stems from the insolubility and precipitation difficulties encountered with high concentrations of the full-length versions of these proteins. A general oligomerization scheme is proposed for this protein family based on the structures of the effector-binding domain of BenM in two different space groups, P4322 and C2221. These structures used the same oligomerization scheme of dimer,dimer interactions as another LysR-type regulator, CbnR, the full-length structure of which is available [Muraoka et al. (2003), J. Mol. Biol.328, 555,566]. Evaluation of packing relationships and surface features suggests that BenM can form infinite oligomeric arrays in crystals through these dimer,dimer interactions. By extrapolation to the liquid phase, such dimer,dimer interactions may contribute to the significant difficulty in crystallizing full-length members of this family. The oligomerization of dimeric units to form biologically important tetramers appears to leave unsatisfied oligomerization sites. Under conditions that favor association, such as neutral pH and concentrations appropriate for crystallization, higher order oligomerization could cause solubility problems with purified proteins. A detailed model by which BenM and other LysR-type transcriptional regulators may form these arrays is proposed. [source]