Related Experiment Videos
The plasmid cloning vector pBR325 contains a 482 base-pair-long inverted duplication
Gene
|September 1, 1981
Summary
The plasmid pBR325, a cloning vector, contains a chloramphenicol resistance gene. It also features an inverted duplication that may impact cloning experiments.
Area of Science:
- Molecular Biology
- Genetics
- Biotechnology
Background:
- pBR325 is a widely used cloning vector derived from pBR322.
- It was engineered by incorporating a chloramphenicol resistance (Cmr) gene from an IS1-flanked transposon.
- The plasmid lacks IS1 sequences but contains a Cmr segment potentially from a transposon larger than Tn9.
Purpose of the Study:
- To characterize the genetic structure of the pBR325 cloning vector.
- To investigate the presence and implications of a specific DNA sequence arrangement within pBR325.
- To analyze the potential impact of structural features on cloning efficiency.
Main Methods:
- DNA sequencing to determine the precise genetic makeup of pBR325.
- Comparative analysis of pBR325 with its parent plasmid pBR322 and related derivatives like pBR328.
- Bioinformatic analysis to identify structural elements and their potential functions.
Main Results:
- pBR325 is a 5,995 bp plasmid.
- It contains an inverted duplication of a 482 bp sequence located between the Cmr and tetracycline resistance (Tcr) genes.
- This inverted duplication mirrors a section of pBR322 near the end of the Tcr gene.
Conclusions:
- The Cmr gene in pBR325 originates from a transposon distinct from Tn9.
- The identified inverted duplication in pBR325 is also present in its deletion derivative pBR328.
- The structural arrangement, particularly the inverted duplication, may have significant implications for cloning experiments utilizing these vectors.