Identification of substituent groups and related genes involved in salecan biosynthesis in Agrobacterium sp ZX09
Identification of substituent groups and related genes involved in salecan biosynthesis in Agrobacterium sp ZX09
复制标题
农杆菌ZX09中参与salecan生物合成的取代基和相关基因的鉴定
DOI：
10.1007/s00253-016-7814-z
复制
发表时间：
2017
影响因子：
5
通讯作者：
Zhang Jianfa
中科院分区：
文献类型：
--
作者：
Xu Linxiang;Cheng Rui;Li Jing;Wang Yang;Zhu Bin;Ma Shihong;Zhang Weiming;Dong Wei;Wang Shiming;Zhang Jianfa
Salecan是由耐盐土壤杆菌（Agrobacteriumsp.）ZX09由于其多种生物活性和溶液中不寻常的流变学性质，近年来一直是人们相当感兴趣的主题。在这项研究中，通过核磁共振（NMR）、高效液相色谱（HPLC）和MS分析后的酶促水解来鉴定salecan上的琥珀酰和丙酮酰取代基。确定并克隆了推定的琥珀酰转移酶基因（sleA）和琥珀酰转移酶基因（sleV）。破坏thesleA基因导致在salecan上没有琥珀酰取代基。这种缺陷可以通过在质粒中表达克隆的sleA来补充。因此，位于一个19.6kb基因簇中的sleA和sleV基因可能参与salecan的生物合成。尽管缺乏琥珀酰取代基，由thesleA突变体产生的salecan的分子量没有实质性的差异，从野生型菌株产生的。琥珀酰取代基的丧失改变了salecan的流变特性，特别是特性粘度的降低。
Salecan, a soluble β-1,3-d-glucan produced by a salt-tolerant strainAgrobacteriumsp. ZX09, has been the subject of considerable interest in recent years because of its multiple bioactivities and unusual rheological properties in solution. In this study, both succinyl and pyruvyl substituent groups on salecan were identified by an enzymatic hydrolysis following nuclear magnetic resonance (NMR), HPLC, and MS analysis. The putative succinyltransferase gene (sleA) and pyruvyltransferase gene (sleV) were determined and cloned. Disruption of thesleAgene resulted in the absence of succinyl substituent groups on salecan. This defect could be complemented by expressing thesleAcloned in a plasmid. Thus, thesleAandsleVgenes located in a 19.6-kb gene cluster may be involved in salecan biosynthesis. Despite the lack of succinyl substituents, the molecular mass of salecan generated by thesleAmutant did not substantially differ from that generated by the wild-type strain. Loss of succinyl substituents on salecan changed its rheological characteristics, especially a decrease in intrinsic viscosity.