Impact of natural variation in bacterial F17G adhesins on crystallization behaviour

URL:

Keywords:

Abstract:

Since the introduction of structural genomics, the protein has been recognized as the most important variable in crystallization. Recent strategies to modify a protein to improve crystal quality have included rationally engineered point mutations, truncations, deletions and fusions. Five naturally occurring variants, differing in 1-18 amino acids, of the 177-residue lectin domain of the F17G fimbrial adhesin were expressed and purified in identical ways. For four out of the five variants crystals were obtained, mostly in non-isomorphous space groups, with diffraction limits ranging between 2.4 and 1.1 A resolution. A comparative analysis of the crystal-packing contacts revealed that the variable amino acids are often involved in lattice contacts and a single amino-acid substitution can suffice to radically change crystal packing. A statistical approach proved reliable to estimate the compatibilities of the variant sequences with the observed crystal forms. In conclusion, natural variation, universally present within prokaryotic species, is a valuable genetic resource that can be favourably employed to enhance the crystallization success rate with considerably less effort than other strategies

Notes:

DA - 20050725 IS - 0907-4449 (Print) LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't RN - 0 (Adhesins, Bacterial) RN - 0 (Disaccharides) RN - 0 (Escherichia coli Proteins) RN - 0 (F17-G adhesin protein, E coli) SB - IM