title: [Cloning and characterization of gene cluster for biosynthesis of ectoine and 5-hydroxyectoine from extreme halotolerant actinomycete strain Prauserella alba YIM 90005(T)].
abstract: OBJECTIVE
  To study adaptive mechanism in hypersaline environments of extreme halotolerant filamentous actinomycetes.
  
  
  METHODS
  Using HPLC we analyzed compatible solutes from extreme halotolerant filamentous actinomycete strain Prauserella alba YIM 90005T that was cultivated at different NaCI concentrations.
  
  
  RESULTS
  Ectoine and 5-hydroxyectoine were two major compatible solutes for strain Prauserella alba YIM 90005T. Ectoine accumulated to the maximum content of 18.77 microg/mg dry cell weight after being inoculated in 10% NaCl (w/v). And 5-hydroxyectoine reached 22.98 microg/mg dry cell weight after being inoculated in 24% NaCl (w/v). The ectA (acyltransferase), ectB (aminotransferase), ectC (ectoine synthase) and ectD (ectoine hydroxylase) genes cluster encoding genes on ectoine and hydroxyectoine synthesis were further cloned by designing the degenerate primer and genome walking methods. The sequence analysis indicated that ectABCD was an operon. Furthermore, the expression of ectB and ectD inoculated at different salt concentrations was quantified by real-time PCR, and the results indicated that the expression of the gene cluster would be increasing as the salt concentration increased.
  
  
  CONCLUSIONS
  5-hydroxyectoine was the major compatible solute for osmotic regulation of strain Prauserella alba YIM 90005T to adapt high salt concentration.
authors.affiliation: Key Laboratory for Microbial Resources of the Ministry of Education, Yunnan Institute of Microbiology, Yunnan University, Kunming 650091, China. liyan0709@hotmail.com
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Lei
authors.initials: L
authors.lastname: Dong
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.forename: Fujin
authors.initials: F
authors.lastname: Fang
authors.forename: Min
authors.initials: M
authors.lastname: He
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Cao
authors.forename: Yuan
authors.initials: Y
authors.lastname: Liang
authors.forename: Shukun
authors.initials: S
authors.lastname: Tang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Li
mesh_terms: D000192:Actinomycetales / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000599:Amino Acids, Diamino / Q000032:analysis / Q000096:biosynthesis* / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D006836:Hydro-Lyases / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D009997:Osmotic Pressure; D017422:Sequence Analysis, DNA; D012965:Sodium Chloride / Q000494:pharmacology; D000637:Transaminases / Q000235:genetics / Q000378:metabolism
chemical_list: D000599:Amino Acids, Diamino; D001426:Bacterial Proteins; C121557:hydroxyectoine; D012965:Sodium Chloride; C045628:ectoine; D000217:Acyltransferases; D000637:Transaminases; D006836:Hydro-Lyases; C106231:ectoine synthase