1N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia.
2School of Molecular Bioscience, The University of Sydney, Sydney, Australia.
Microbiology (Reading). 2018 Oct;164(10):1289-1292. doi: 10.1099/mic.0.000710. Epub 2018 Aug 13.
The KL53 capsular polysaccharide (CPS) gene cluster of Acinetobacter baumannii D23 was sequenced, and includes a single gtr gene encoding the glycosyltransferase Gtr2, and the itrA1 gene for ItrA1 that is known to initiate CPS biosynthesis with d-QuiNAc4NAc. The K53 CPS was isolated and studied by one- and two-dimensional H and C nuclear magnetic resonance (NMR) spectroscopy before and after O-deacetylation. The disaccharide K unit of the CPS was established as →3)-α-d-GalpNAcA4Ac-(1→3)-β-d-QuipNAc4NAc-(1→, where GalNAcA and QuiNAc4NAc indicate 2-acetamido-2-deoxygalacturonic acid and 2,4-diacetamido-2,4,6-trideoxyglucose, respectively. This established the linkage formed by Gtr2. The degree of 4-O-acetylation of d-GalNAcA by Atr18, encoded at the KL53 locus, is ~55 %.
鲍曼不动杆菌 D23 的 KL53 荚膜多糖 (CPS) 基因簇被测序，其中包括编码糖基转移酶 Gtr2 的单个 gtr 基因，以及已知用 d-QuiNAc4NAc 启动 CPS 生物合成的 itrA1 基因。在 O-去乙酰化前后，通过一维和二维 H 和 C 核磁共振 (NMR) 光谱对 K53 CPS 进行了分离和研究。CPS 的二糖 K 单元被确定为→3）-α-d-GalpNAcA4Ac-（1→3）-β-d-QuipNAc4NAc-（1→，其中 GalNAcA 和 QuiNAc4NAc 分别表示 2-乙酰氨基-2-脱氧半乳糖醛酸和 2,4-二乙酰氨基-2,4,6-三脱氧葡萄糖。这确立了 Gtr2 形成的键。由 KL53 基因座编码的 Atr18 对 d-GalNAcA 的 4-O-乙酰化程度约为 55%。
