Question

ΦΧ174 Rolling circle

replication:

Proteins needed for rolling circle replication:
____ ____ to nick at origin (pas). Covalently linked to 5'end of the displaced strand.
___ protein to keep DNA single-stranded. Binding is highly cooperative.
___ protein provides helicase function. (DNAB also participates)
____ ____ ____ holoenzyme

** which proteins are provided by host?

Answer 1

Proteins needed for ΦX174 Rolling Circle replication include an enzyme to nick at the origin, a single-strand binding protein, a helicase, and DNA polymerase III holoenzyme from the host.

Step-by-step explanation:

For the ΦX174 Rolling Circle replication, proteins are needed to facilitate the replication process:

• An enzyme to nick at origin (pas): This is usually a specific replication initiation protein that becomes covalently linked to the 5' end of the displaced strand.
• A single-strand binding (SSB) protein to keep DNA single-stranded. Binding of these proteins is highly cooperative to stabilize the DNA.
• A helicase protein provides helicase function, unwinding the DNA at the replication fork. DNAB, provided by the host, also participates in this unwinding process.
• The DNA polymerase III holoenzyme is responsible for synthesizing new DNA strands; it's provided by the host organism.

Topoisomerase, such as DNA gyrase, and helicase are essential for initiating replication by relaxing the supercoiled DNA and separating the DNA strands, respectively. Single-strand binding proteins then protect the unwound DNA from reannealing, and the DNA polymerase, using primers, adds nucleotides to synthesize the new DNA strand.