178-Nucleotide sequence surrounding the cos site of bacteriophage lambda DNA

Area of Science:

• Molecular Biology
• Genetics
• Virology

Background:

• Bacteriophage lambda (λ) is a vital model organism in molecular biology research.
• Understanding the genetic structure of bacteriophage DNA is crucial for deciphering viral replication and evolution.

Purpose of the Study:

• To determine the nucleotide sequences at the left and right ends of bacteriophage lambda (λ) DNA.
• To identify and characterize inverted repeat sequences within these DNA regions.
• To compare sequence divergence between closely related bacteriophage lambda (λ) strains.

Main Methods:

• DNA sequencing using the Maxam and Gilbert method.
• Analysis of nucleotide sequences to identify inverted repeat structures.

Main Results:

• Determined 61 nucleotides at the left end and 117 nucleotides at the right end of bacteriophage lambda (λ) DNA (strain I857Sam7).
• Identified a 10-nucleotide perfect inverted repeat near the left DNA end and a 15-nucleotide perfect inverted repeat near the right DNA end.
• Observed approximately 10% sequence divergence in the first 110 nucleotides of the right DNA end in a related strain (I857prm116Sam7), which also possessed a 17-nucleotide perfect inverted repeat.

Conclusions:

• The ends of bacteriophage lambda (λ) DNA contain significant inverted repeat sequences.
• Sequence divergence exists between closely related bacteriophage lambda (λ) strains, particularly in specific DNA regions.
• Inverted repeats may play roles in the genetic stability or regulation of bacteriophage lambda (λ).