Final answer:
In E. coli, the DNA polymerase III holoenzyme adds nucleotides at a rate of approximately 1000 nucleotides per second during DNA replication.
Step-by-step explanation:
In E. coli, the DNA polymerase III holoenzyme, which includes the B subunit, is an essential component of the DNA replication machinery. This holoenzyme can add nucleotides at an impressive rate, with the replication fork moving at around 1000 nucleotides per second. This rapid addition contributes to the efficient replication of E. coli's 4.6 million base pair circular chromosome in approximately 42 minutes, ensuring the process is both rapid and accurate with few errors occurring during replication.