1.RESTRICTION FRAGMENT LENGTH POLYMORPHISM (RFLP) OF ADHESIN GENE HPA A FROM DIFFERENT HELICOBACTER PYLORI STRAINS
Yu HONG ; Quanming ZOU ; Xuhu MAO ; Shenrong JING ;
Microbiology 1992;0(03):-
To assess the variability of adhesin gene hpaA in differene H pyloristrains with PCR restriction fragment length polymorphism (RFLP) A 710 bp gene hpaA , obtained from 9 different H pylori strains, were digested by Hha Ⅰand Hae Ⅲ individually and analyzed by agarose gel electrophoresis Four different polymorphic types were found in hpaA digested with Hae III and five types with Hha I Clinical isolates of H pylori from Chongqing showed difference among them and remarkably distinguished from foreign standard strains Mongolia gerbil adapted H pylori strain,which were obtained from Mongolia gerbil infected with clinical isolate, also showed inconsistence in hpaA RFLP The hpaA gene from different H pylori strains revealed 1 variability, and this might provide an effective method for developing molecular epidemiology of H pylori
2.The analysis of promoters and the effective expression of exogenous proteins in a cold-adapted bacterium.
Yunlin WEI ; Xiuling JI ; Lianbing LIN ; Shenrong JING
Chinese Journal of Biotechnology 2008;24(3):415-422
Based on the constructed promoter probe vectors that could replicate both in E. coli and in a cold-adapted bacterium, several candidate promoters were isolated and their activities were evaluated by RT-PCR. The transcription initiation sites and core sequence of promoters were determined by primer extension analysis. A low-temperature expression vector was constructed by using the strongest promoter and a thermolabile alpha-amylase gene was successfully overproduced under control of this promoter at low temperature (7 degrees C), while the secreted alpha-amylase amounted up to 35% of the total extracellular proteins. The expression system is expected to be useful for the production of thermolabile exogenous proteins at low temperatures.
Acinetobacter
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genetics
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metabolism
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Adaptation, Physiological
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genetics
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Bacterial Proteins
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biosynthesis
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genetics
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Base Sequence
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Cold Temperature
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Escherichia coli
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genetics
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metabolism
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Genetic Vectors
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genetics
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Molecular Sequence Data
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Promoter Regions, Genetic
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genetics
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Transformation, Genetic
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alpha-Amylases
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biosynthesis
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genetics
3.Cloning and characterization of the chloramphenicol resistant gene of Serratia marcescens strain KMR-3.
Xiuling JI ; Lianbing LIN ; Shenrong JING ; Yunlin WEI
Chinese Journal of Biotechnology 2008;24(6):1016-1021
Chloramphenicol-resistant gene was cloned and analyzed by constructing genomic DNA library of Serratia marcescens KMR-3. It showed that cloned chloramphenicol-resistant gene encoded a protein product of 397 amino acids. The protein belonged to PRK10473 protein, and it showed 92% similarity to drug resistance transporter, Bcr/CflA subfamily of Serratia proteamaculans 568. Regulation elements including promoter, terminator, Shine-Dalgarno (SD) sequence and transcription start site also were identified.
Amino Acid Sequence
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Base Sequence
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Chloramphenicol Resistance
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genetics
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Cloning, Molecular
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Molecular Sequence Data
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Serratia marcescens
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classification
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genetics