The nucleotide sequence surrounding the replication terminus of R6K

Area of Science:

• Molecular Biology
• Genetics
• Biochemistry

Background:

• The plasmid R6K replication terminus is crucial for controlling DNA replication.
• Understanding the molecular mechanisms of replication termination is essential in genetics.

Purpose of the Study:

• To determine the DNA sequence of the R6K plasmid replication terminus.
• To investigate the structural features and potential mechanisms of replication termination.

Main Methods:

• Cloning the R6K replication terminus into M13mp5, pBR313, and PBR322 vectors.
• Utilizing single-stranded DNA templates from recombinant clones for DNA sequencing.
• Analyzing the DNA sequence for structural motifs like 2-fold rotational symmetry.

Main Results:

• The DNA sequence of the 215 base pair replication terminus was successfully determined.
• No significant 2-fold rotational symmetry was found in the DNA sequence of the terminus.
• The absence of symmetry suggests DNA folding is not the primary termination mechanism.

Conclusions:

• Replication termination at the R6K terminus is unlikely due to DNA secondary structures.
• A host-specified protein interacting with the terminus DNA sequence is the probable cause of replication termination.