W0145

Homology Model of the N-acetylglucosamine 6-phosphate Deacetilase from Escherichia coli Obtained from Solution SAXS Data. Frederico Moraes Ferreira, Hannes Fischer, Aldo F. Craievich, Glaucius Oliva, Dept. of Physics and Informatics, Univ. of São Paulo, Av Trabalhador Sancarlense, 400, São Carlos, SP 13560970 BRAZIL.

The goal of the present work has been to restore the oligomeric organization and the tetramerization interface of the N-acetylglucosamne 6-phosphate deacetilase (desacetilase) from Escherichia coli based on solution synchrotron SAXS data. For this purpose the SAXS curves from deacetilase in solution where used to fit the scattering amplitudes of a homology model of deacetilase. This protein exhibits a very globular and compact shape as revealed by SAXS data analysis.

Deacetylase catalyses the conversion as N-acetylglucosamine 6-phosphate into glucosamine 6-phosphate and acetate and as such forms part of the pathway for aminosugar utilization in E. coli. Such protein has been purified from overexpression from Escherichia coli and has been crystallized by vapor diffusion technique with phosphate as precipitant. Sequence alignment experiments have shown low homology (29%) with deacetilase from Themotoga maritima and the molecular replacement is currently underway aiming E. coli deacetylase full-three dimensional structure and elucidation of its catalytic mechanism.

Structure solution using diffraction data is underway, we also might compare the solution structure with its crystallographic one and discuss eventual changes.