Structures of capsular polysaccharides of Acinetobacter baumannii isolates carrying KL13 and KL73 gene clusters were established. The closely related KL73 and KL13 gene clusters differ only by one gene in the module responsible for synthesis of the non-2-ulosonic acids. The K13 and K73 polysaccharides differ only in a single side-chain sugar, which is either 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-altro- or -D-glycero-L-altro-non-2-ulosonic acid [di-N-acetylated forms of acinetaminic acid (Aci5Ac7Ac) or 8-epiacinetaminic acid (8eAci5Ac7Ac), respectively]. The KL13 also is closely related to the KL12 gene cluster, which contains a different wzy gene encoding the K unit polymerase. Accordingly, the otherwise near identical K units are linked differently via an a-DFucpNAc-(1 /4)-D-Galp linkage in K13 and K73 or an a-D-FucpNAc-(1 /3)-D-GalpNAc linkage in K12. This finding confirms the predicted substrate of the ItrB3 initiating transferase as D-FucpNAc. Glycosyltransferases predicted to catalyse the linkage of D-Galp or D-GalpNAc to L-FucpNAc in the growing K13 and K73 or K12 units, respectively, differ by only two amino acids.
Acinetobacter baumannii K13 and K73 capsular polysaccharides differ only in K-unit side branches of novel non-2-ulosonic acids: di-N-acetylated forms of either acinetaminic acid or 8-epiacinetaminic acid / Kenyon, Johanna J.; Kasimova, Anastasiya A.; Notaro, Anna; Arbatsky, Nikolay P.; Speciale, Immacolata; Shashkov, Alexander S.; De Castro, Cristina; Hall, Ruth M.; Knirel, Yuriy A.. - In: CARBOHYDRATE RESEARCH. - ISSN 0008-6215. - 452:(2017), pp. 149-155. [10.1016/j.carres.2017.10.005]
Acinetobacter baumannii K13 and K73 capsular polysaccharides differ only in K-unit side branches of novel non-2-ulosonic acids: di-N-acetylated forms of either acinetaminic acid or 8-epiacinetaminic acid
Notaro, AnnaMembro del Collaboration Group
;Speciale, ImmacolataMembro del Collaboration Group
;De Castro, Cristina
Writing – Review & Editing
;
2017
Abstract
Structures of capsular polysaccharides of Acinetobacter baumannii isolates carrying KL13 and KL73 gene clusters were established. The closely related KL73 and KL13 gene clusters differ only by one gene in the module responsible for synthesis of the non-2-ulosonic acids. The K13 and K73 polysaccharides differ only in a single side-chain sugar, which is either 5,7-diacetamido-3,5,7,9-tetradeoxy-L-glycero-L-altro- or -D-glycero-L-altro-non-2-ulosonic acid [di-N-acetylated forms of acinetaminic acid (Aci5Ac7Ac) or 8-epiacinetaminic acid (8eAci5Ac7Ac), respectively]. The KL13 also is closely related to the KL12 gene cluster, which contains a different wzy gene encoding the K unit polymerase. Accordingly, the otherwise near identical K units are linked differently via an a-DFucpNAc-(1 /4)-D-Galp linkage in K13 and K73 or an a-D-FucpNAc-(1 /3)-D-GalpNAc linkage in K12. This finding confirms the predicted substrate of the ItrB3 initiating transferase as D-FucpNAc. Glycosyltransferases predicted to catalyse the linkage of D-Galp or D-GalpNAc to L-FucpNAc in the growing K13 and K73 or K12 units, respectively, differ by only two amino acids.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.