Identification of substituent groups and related genes involved in salecan biosynthesis in Agrobacterium sp. ZX09.
Salecan, a soluble β-1,3-D-glucan produced by a salt-tolerant strain Agrobacterium sp. 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 the sleA gene resulted in the absence of succinyl substituent groups on salecan. This defect could be complemented by expressing the sleA cloned in a plasmid. Thus, the sleA and sleV genes 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 the sleA mutant 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.
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Linxiang
L
Xu
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Rui
R
Cheng
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Jing
J
Li
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Yang
Y
Wang
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Bin
B
Zhu
Nanjing Institute for the Comprehensive Utilization of Wild Plant, China-COOP, Nanjing, 210052, China.
Shihong
S
Ma
Nanjing Institute for the Comprehensive Utilization of Wild Plant, China-COOP, Nanjing, 210052, China.
Weiming
W
Zhang
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Wei
W
Dong
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China.
Shiming
S
Wang
Center for Molecular Metabolism, Nanjing University of Science and Technology, 200 Xiao ling wei Street, Nanjing, 210094, China. jfzhang@mail.njust.edu.cn.
Jianfa
J
Zhang
D060054:Agrobacterium / Q000235:genetics* / Q000378:metabolism*; D053898:Biosynthetic Pathways / Q000235:genetics*; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D017353:Gene Deletion; D005816:Genetic Complementation Test; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D005810:Multigene Family; D011773:Pyruvates / Q000737:chemistry / Q000378:metabolism; D013386:Succinates / Q000737:chemistry / Q000378:metabolism; D014166:Transferases / Q000235:genetics; D047071:beta-Glucans / Q000737:chemistry / Q000378:metabolism*
D011773:Pyruvates; D013386:Succinates; D047071:beta-Glucans; C577623:salecan; D014166:Transferases
Agrobacterium sp. ZX09; Gene cluster; Rheology; Salecan; Substituent