4. The necessary components for gene expression
are often described as either cis-acting elements (“acting
from the same molecule”) or trans-acting factors (“acting
from a different molecule”). Cis-acting elements are
typically sequences that are required for expression.
Trans-acting factors are typically proteins that recognize
and bind cis-acting sequences to control or facilitate
gene expression. For each of the trans-acting factors
below, describe their enzymatic activity and one of their
cis-acting target sequences. [8 pts; 4 pts each]

4a. RNA Polymerase

4b. Ribosome