1l3l

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spinqualitylabelsall models 1l3l, resolution 1.66Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of a bacterial quorum-sensing transcription factor complexed with pheromone and DNA

Overview

Many proteobacteria are able to monitor their population densities through, the release of pheromones known as N-acylhomoserine lactones. At high, population densities, these pheromones elicit diverse responses that, include bioluminescence, biofilm formation, production of antimicrobials, DNA exchange, pathogenesis and symbiosis. Many of these regulatory systems, require a pheromone-dependent transcription factor similar to the LuxR, protein of Vibrio fischeri. Here we present the structure of a LuxR-type, protein. TraR of Agrobacterium tumefaciens was solved at 1.66 A as a, complex with the pheromone N-3-oxooctanoyl-L-homoserine lactone (OOHL) and, its TraR DNA-binding site. The amino-terminal domain of TraR is an, alpha/beta/alpha sandwich that binds OOHL, whereas the carboxy-terminal, domain contains a helix turn helix DNA-binding motif. The TraR dimer, displays a two-fold symmetry axis in each domain; however, these two axes, of symmetry are at an approximately 90 degree angle, resulting in a, pronounced overall asymmetry of the complex. The pheromone lies fully, embedded within the protein with virtually no solvent contact, and makes, numerous hydrophobic contacts with the protein as well as four hydrogen, bonds: three direct and one water-mediated.

About this Structure

1L3L is a Single protein structure of sequence from Agrobacterium tumefaciens with LAE as ligand. Full crystallographic information is available from OCA.

Reference

Structure of a bacterial quorum-sensing transcription factor complexed with pheromone and DNA., Zhang RG, Pappas T, Brace JL, Miller PC, Oulmassov T, Molyneaux JM, Anderson JC, Bashkin JK, Winans SC, Joachimiak A, Nature. 2002 Jun 27;417(6892):971-4. PMID:12087407

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