The K92 capsular polysaccharide (CPS) from Acinetobacter baumannii B8300 was studied by sugar analysis, Smith degradation, and one- and two-dimensional ¹H and ¹³C NMR spectroscopy. The elucidated CPS includes a branched pentasaccharide repeat unit containing one d-Galp and four l-Rhap residues; an atypical composition given that all A. baumannii CPS structures determined to date contain at least one amino sugar. Accordingly, biosynthesis of A. baumannii CPS types are initiated by initiating transferases (Itrs) that transfer 1-phosphate of either a 2-acetamido-2-deoxy-d-hexose, a 2-acetamido-2,6-dideoxy-d-hexose or a 2-acetamido-4-acylamino-2,4,6-trideoxy-d-hexose to an undecaprenyl phosphate (UndP) carrier. However, the KL92 capsule biosynthesis gene cluster in the B8300 genome sequence includes a gene for a novel Itr type, ItrA4, which is predicted to begin synthesis of the K92 CPS by transferring D-Galp 1-phosphate to the UndP lipid carrier. The itrA4 gene was found in a module transcribed in the opposite direction to the majority of the K locus. This module also includes an unknown open reading frame (orf_KL92), a gtr166 glycosyltransferase gene, and a wzi gene predicted to be involved in the attachment of CPS to the cell surface. Investigation into the origins of orf_KL92-gtr166-itrA4-wzi_KL92 revealed it might have originated from Acinetobacter junii.

通过糖分析、Smith 降解以及一维和二维¹ H 和¹³ C NMR 光谱研究了鲍曼不动杆菌B8300的 K92 荚膜多糖 (CPS) 。阐明的CPS包括含有一个d- Gal p和四个l- Rha p残基的支链五糖重复单元；考虑到迄今为止确定的所有鲍曼不动杆菌CPS 结构都包含至少一种氨基糖，这是一种非典型组成。因此，鲍曼不动杆菌CPS 类型的生物合成是通过启动转移酶 (Itrs) 启动的，该酶转移 2-乙酰氨基-2-脱氧-d-hexose，2-乙酰氨基-2,6-二脱氧d -hexose或2-乙酰氨基-4-酰氨基-2,4,6-三脱氧d -hexose到十一异戊烯磷酸（署）的载体。然而，B8300 基因组序列中的 KL92 荚膜生物合成基因簇包括一个新的 Itr 类型 ItrA4 的基因，预计它会通过将 D-Gal p 1-磷酸转移到 UndP 脂质载体来开始合成 K92 CPS 。所述itrA4基因以相反的方向转录到多数K个基因座的一个模块中被发现。该模块还包括一个未知的开放阅读框 ( orf _KL92 )、一个gtr166糖基转移酶基因和一个wzi基因预测参与 CPS 附着到细胞表面。对orf _KL92 - gtr166-itrA4-wzi _KL92起源的调查显示它可能起源于六月不动杆菌。