ABSD: Acinetobacter baumannii K-antigen three-dimensional Structure Database

K antigens or capsular polysaccharides (CPS) are repeating units of sugars linked by glycosidic linkages. The sugar composition and the linkages have been determined by chemical, enzymatic methods so far, some of which include methylation analysis, bacteriophage borne endo-glycanases, and Smith degradation analysis. These methods have been further supported by ¹H- and ¹³C-NMR. (Nuclear magnetic resonance) spectra, ORD (Optical rotatory dispersion) and CD (Circular dichroism) spectra of the oligosaccharides.The database comprises three dimensional structures of the K antigens, that were modeled in GLYCAM web server (Woods Group. (2005-2015) GLYCAM Web. Complex Carbohydrate Research Center, University of Georgia, Athens, GA. (http://www.glycam.com)) and were subsequently minimized by CHARMM 36 forcefield. Classification of KL serotypes based on the initial transferases can be referred from the documentaion (itrs)

Click on the links below to get 3D structural information on the antigen
All schematic representations of CPS repeating units are grouped majorly into six categories based on their first monomers : (i) bacillosamine (ItrA1), (ii) N-acetyl-D-galactosamine (ItrA2), (iii) N-acetyl-D-glucosamine (ItrA3),(iv) D-galactose (ItrA4), (v) N-acetyl-D-quinovosamine or N-acetyl-L-fucosamine (ItrB1), (vi) N-acetyl-D-glucosamine (Itr A3,B2), (vii) N-acetyl-L-fucosamine (ItrB3).