Final answer:
The proteins necessary to maintain the separated strands during PhiX174 replication are DnaB (helicase) and SSB (option a) (single-strand binding proteins). Helicase unwinds the DNA at the origin of replication, and SSB proteins stabilize the unwound strands to prevent reannealing.
Step-by-step explanation:
The proteins necessary to maintain the separated strands during PhiX174 replication of the leading strand are DnaB (helicase) and SSB (single-strand binding proteins). Helicase is responsible for unwinding and separating the double-stranded DNA to allow replication to take place. Following this, single-strand binding proteins stabilize the unwound strands to prevent them from reannealing or forming secondary structures. This creates a suitable template for DNA synthesis by DNA polymerase.
Helicase unwinds DNA at the origin of replication, whereas single-strand binding proteins bind to the strands, keeping them apart. These processes are critical for DNA replication, and without them, the replication fork could not be properly established or maintained. Together, these proteins facilitate the accurate and efficient replication of the leading strand during DNA synthesis.