Expression, purification, crystallization and preliminary X-ray analysis of the polysaccharide lyase RB5312 from the marine planctomycete Rhodopirellula baltica.

Polysaccharide lyases belonging to family PL1 act on pectins. These anionic polymers are usually produced by terrestrial plants and therefore pectinolytic enzymes are not frequently observed in marine microorganisms. The protein RB5312 from the marine bacterium Rhodopirellula baltica is distantly related to family PL1 pectate lyases, but its exact function is unclear. In this study, the expression and purification of a recombinant form of RB5312 are described. This protein was crystallized using the hanging-drop vapour-diffusion method. The crystals belongs to space group P2(1)2(1)2(1), with unit-cell parameters a = 39.05, b = 144.05, c = 153.97 A, alpha = beta = gamma = 90 degrees. A complete data set was collected to 1.8 A resolution from a native crystal.