The bacteriophage ϕX174 has a single-stranded DNA genome of 5386 bases. During DNA replication, double-stranded forms of the genome are generated. In an effort to create a restriction map of ϕX174, you digest the z-stranded form of the genome with several restriction enzymes and obtain the following results. Draw a map of the ϕX174 genome.

Pstl     5386                PstI + PsiI      3078, 2308
Psil     5386                PstI + DraI      331, 1079, 3976
Dral    4307, 1079      PstI + DraI      898, 1079, 3409

Key Concepts

Bacteriophage Structure and Function

Bacteriophages, like ϕX174, are viruses that infect bacteria. They typically consist of a protein coat surrounding their genetic material, which can be either DNA or RNA. Understanding the structure of ϕX174, particularly its single-stranded DNA genome, is crucial for grasping how it replicates and interacts with host cells during the infection process.

Restriction Enzymes and Digestion

Restriction enzymes are proteins that cut DNA at specific sequences, allowing scientists to manipulate genetic material for various applications, including creating restriction maps. By digesting the double-stranded form of the ϕX174 genome with different enzymes, researchers can determine the locations of these cut sites, which is essential for mapping the genome's structure.

Restriction Mapping

Restriction mapping is a technique used to identify the locations of restriction enzyme cut sites within a DNA molecule. By analyzing the sizes of the resulting DNA fragments after digestion, researchers can infer the arrangement of the genome. This process is vital for understanding the genetic organization of ϕX174 and can aid in further studies of its biology and applications in biotechnology.