[Cloning and sequencing of promoter and signal sequence coding regions from XXXX ].

@entity869 @entity2929 @entity3881 @entity526
Promoter and signal sequence coding regions from @entity3881 were cloned in @entity526 using a bifunctional and signal sequence selection plasmid pGPB14 as a vector. The Sau3A digested chromosome DNA was ligated with BamHI digested pGPB14. The ligated mixture was used to transform @entity526 C600. @entity869 and @entity2929 resistant clones were selected. Recombinant plasmids were isolated from double resistant transformants. Restriction analysis showed that inserts of various length had been cloned and these inserts rendered the @entity526 cells resistant to different concentrations of @entity869 . The recombinant plasmids were transformed and showed the same secretion function in @entity3881 . The amount and localization of beta-lactamase were determined in transformed @entity526 and @entity3881 . The results indicate that the beta-lactamase activities of @entity526 mainly in periplasm while the enzyme produced by @entity3881 secreted extracellularly. 10 of the cloned fragments were sequenced by Sanger's dideoxy chain termination method. The sequencing data show that all fragments contain promoter, ribosome binding site and signal sequence coding region.
