  We discuss the renormalization of local, scalar and pseudoscalar dimension-5
operators containing a heavy and a light quark field at scales below the
heavy-quark mass, using the formalism of the heavy-quark effective theory
(HQET). We calculate the anomalous dimensions of these operators and their
mixing to one-loop order. We also perform the one-loop matching of gluon and
photon penguin operators onto operators of the HQET. We discuss applications of
our results to the mixing of gluon and photon penguin operators at low
renormalization scales, and to the calculation of $1/m_Q^2$ corrections to
meson decays constants.
