CRYSTAL STRUCTURE OF CV-IIL LECTIN FROM HUMAN OPPORTUNISTIC PATHOGEN

M. Pokorná¹, G. Cioci², E. P. Mitchell³, S. Perret², A. Imberty² and M. Wimmerová^1,4

¹National Centre for Biomolecular Research, Masaryk University, Kotlarska 2, 611 37 Brno, Czech Republic

²CERMAV-CNRS, 601 rue de la Chimie, BP 53, 38041 Grenoble, France

³ESRF, Experiments Division, BP 220, 38043 Grenoble, France

⁴Department of Biochemistry, Masaryk University, Kotlarska 2, 611 37 Brno, Czech Republic

Carbohydrates are essential components of life that play crucial role in all organisms. They are very important agent in recognition and signalling ways. Lectin-carbohydrate interactions play a crucial role in many recognition events.

Chromobacterium violaceum is a gram-negative bacterium first described at the end of 19^th century. This bacterium has been found in tropical and subtropical regions, water and borders of the Negro river. Ch. violaceum is an opportunistic pathogen and may cause diseases in immunocompromised individuals [1]. It is phylogenetically related with human pathogen Pseudomonas aeruginosa, which produces PA-IIL lectin, closely related with its virulence.

The contribution is focused on identification and structure-function characterisation of PA-IIL homolog, CV-IIL, found by searching in sequenced bacterial genome of Ch. violaceum [2]

The gene of the protein has been cloned and resulting protein CV-IIL has been purified by affinity chromatography. CV-IIL/a-methyl-D-mannoside and CV-IIL/a-methyl-L-fucoside complexes have been crystallised by hanging drop vapor diffusion method using high-molecular weight PEGs as precipitants. Diffraction data at 1.0 Å resolution were collected under cryogenic conditions (100K) on the beamline ID14-2, at ESFR, Grenoble, France. The crystal structures of CV-IIL in complexes with sugar ligands were solved by molecular replacement. Structure studies together with binding data analysis allowed comparison of
CV-IIL and PA-IIL and brought more detailed view on fine specificity of both lectins.

[1] Ribeiro De Vasconcelos, A.T. & 109 others [Brazilian National Genome Project Consortium]; The complete genome sequence of Chromobacterium violaceum reveals remarkable and exploitable bacterial adaptability. Proc. Natl. Acad. Sci. 100, 11660 (2003)

[2] Imberty A, Wimmerová M, Mitchell E.P., Gilboa-Garber, N. Structures of the lectins from Pseudomonas aeruginosa: Insights into molecular basis for host glycan recognition. Microb. Infect. 6: 222-229 (2004)