Final answer:
The E. coli DNA polymerase III holoenzyme consists of several subunits: two alpha (α) units, and one each of beta (ß), beta prime (ß'), and epsilon (ε) that form the core enzyme, plus a sigma (σ) factor involved in transcription initiation. Among the given choices, the monomeric unit of DNA polymerase III consists of Alpha, Beta, Gamma, and Delta subunits, which makes option 4 the correct answer.
Step-by-step explanation:
The E. coli DNA polymerase III holoenzyme is a complex multi-subunit assembly crucial for DNA replication. This enzyme consists of several different subunits, each performing a unique function during the DNA replication process. In prokaryotes, such as E. coli, this polymerase is composed of five polypeptide subunits.
These subunits include two alpha (α) units, one beta (ß), one beta prime (ß'), and one epsilon (ε) which comprises the core enzyme. There is also a fifth subunit, sigma (σ), that is not part of the core enzyme but plays a critical role in transcription initiation. While the core enzyme is responsible for the polymerization activities, the sigma factor (σ) ensures the specificity of transcription initiation. The assembly of all these units results in what is called the holoenzyme.
Based on the provided options and excluding the sigma subunit which is involved in transcription rather than replication, the correct answer is that the monomeric unit of DNA polymerase III consists of the Alpha, Beta, Gamma, and Delta subunits. Thus, the correct option is 4) Alpha, Beta, Gamma, and Delta subunits.